Nice Way to End the Month...What's Next Month Gonna Bring???

A cool, Fall weekend...loved it. Looks like the first couple of days of November look nice as well. Then some unsettled weather will move back into the region.

What's the month of November looking like so far?

As of today, the Climate Prediction Center has issued its 2-week forecast with above normal temperatures for most of the region, while much below readings across the western U.S.

Precipitation looks to average above normal for our region during the first half of November, including parts of drought-strickened Texas. We'll see about that. Hope they get the rains.

Here's the monthly assessment from the CPC...

Here's a look at the ensembles leading up to the middle of the month of November. This is sure to change. But one thing is certain. Any cold blocked up in the west will eventually have to travel eastward. When it does, that's when it could get quite interesting around our part of the world.

My winter weather forecast is coming out this week. Look for it and compare with others.

Have a good day...

MS

First Significant Regional Winter Storm For East Coast

Click HERE for latest web cam shot of Harrisburg/Lancaster PA where 4-8" of wet snow expected through tomorrow. Winter Storm Warning products out for much of the forecast area there while Winter Storm Watches are posted all along the east coast.

As expected, the far southeastern part of Kentucky will be most impacted by this same weather system that will pronounce winter upon much of the northeast United States.

Already, sleet and some spotty snowflakes have been reported in eastern KY

Although I preferred the other 3 models instead of the European, dry conditions have prevailed for our area here in Louisville as expected. Nevertheless, clouds are hanging tough despite some areas, perhaps just 10 miles from my location, are seeing abundant sunshine.

I forecasted 40's and low 50's for our area the other day and mentioned that southeastern parts of the state would possibly get in on some of the precipitation. I used a compromise of the GFS and GEM solutions to get at what the European model did very well showing.

More updates to follow as the impacts of the first regionwide winter storm for the east coast commences....

MS

No Big Deal...

The much advertised system is finally becoming figured out. After much debate about how certain troughs would affect the region, I'm starting to see a consensus that I'm satisfied with. At this point, I'm relying on the NAM, GFS, and GEM. These outnumber the European model and make more sense according to past analogs.

A decent shot of cold air will pour into the region. Highs still look to struggle to reach 50 degrees especially on Thursday while at least low 50's on Friday. With precip exiting, except possibly the far southeastern part of the state, High pressure builds in and provides cool but calmer conditions by Friday.

I still like the chances of a mild end to this month and the beginning of next month.

In the meantime, look for healthy amounts of rain for the region, especially near Louisville, where over an inch is possible tonight into the first part of tomorrow.

MS

Other Thoughts About the Next System

Well, we have this storm system bound to take shape very soon now. The models are spitting the data out, and the various NWS offices are now offering their thoughts about it. So, here it goes:

NWS Louisville

A sfc wave along the front as well as a mid
level speed max ahead of the approaching upper trough and
strengthening of the right rear region of the 300mb jet will enhance
rainfall Wed night into early Thurs morning...we should see a good 1-2 inch rain area
wide from this system...By Thurs night, another reinforcing trough will dive south out of
Canada into the Midwest while a second weakening trough moves ENE
out of TX/OK into the TN valley. Models differ on the evolution of
these troughs...Thurs and Fri will be much cooler behind the front in
the 50s for highs...maybe even a few upper 40s.
-----------------------------------------

NWS Jackson

THE 00Z RUN OF THE ECMWF IS
SLOWER WITH THIS FEATURE AND ALLOWS THE SURFACE FRONT AND ITS
MOISTURE TO EXIT TO THE SE THURSDAY NIGHT...WITH PRECIP THEN
RETURNING LATE FRIDAY OR FRIDAY NIGHT AS THE UPPER IMPULSE
APPROACHES AND PASSES. THE 00Z ECMWF EVEN LOOKS COLD ENOUGH FOR SNOW
ON OUR RIDGES IN THE SE ON FRIDAY NIGHT. WITH POOR INTER-MODEL
AGREEMENT AND POOR INTRA-MODEL CONSISTENCY...FORECAST CONFIDENCE IS
LOW FOR THURSDAY NIGHT THROUGH FRIDAY NIGHT. ..THE GFS
CONTINUES TO LEAD THE PACK...MOVING DRIER AIR INTO ERN KY ON FRIDAY
BEHIND THE DEPARTING FRONT AND THIS WOULD EFFECTIVELY PRECLUDE ANY
REAL CHANCES FOR PRECIP AFTER THURSDAY NIGHT. A QUICK PEAK AT THE
INCOMING 25.00Z EURO INDICATES SOME CONSISTENCY WITH THE 24.12Z RUN
WHICH HAS BEEN...AND CONTINUES TO REPRESENT THE SLOWER END OF THE
SPECTRUM...BUT DID COME IN A TICK FASTER...SUGGESTING A POSSIBLE
TREND TOWARDS THE MORE MIDDLE OF THE ROAD GEM SOLUTION.

NWS Paducah

BY THURSDAY NIGHT...WE HAD A DRY FORECAST GOING SINCE IT APPEARED
THE POST FRONTAL RAINS WOULD BE OUT OF THE AREA BY THEN. HOWEVER...
THE GEM AND ECMWF MODELS NOW SHOW PRECIP CONTINUING INTO THURSDAY
NIGHT. ..THE FACT
THAT THE ONCE DRY ECMWF IS NOW MORE IN LINE WITH THE GEM MAKES ONE
WONDER IF IT IS PICKING UP ON SOMETHING. WILL HAVE TO WATCH THE GFS
TO SEE IF IT BEGINS TO MIGRATE TOWARD THE GEM/ECMWF.

NWS Indianapolis

A COOLER DRIER AIRMASS WILL OVERSPREAD MUCH OF THE OHIO VALLEY AND
GREAT LAKES ON FRIDAY IN WAKE OF THE MIDWEEK COLD FRONT. 00Z ECMWF
AND TO A LESSER EXTENT THE 00Z GGEM BOTH HANG THE FRONTAL BOUNDARY
UP IN THE EASTERN TENNESSEE VALLEY ON FRIDAY AND THUS KEEP SOME
PRECIP IN THE OHIO VALLEY ON FRIDAY/FRIDAY NIGHT. THIS APPEARS TO BE
THE RESULT OF A MORE AMPLIFIED UPPER DISTURBANCE ROTATING INTO THE
GREAT LAKES LATE DAY FRIDAY. PREFER THE OP GFS/GFS ENSEMBLE MEAN
IDEA OF MORE PROGRESSIVE FLOW ALOFT WITH THE FRONT PUSHING WELL
SOUTHEAST OF THE REGION BY FRIDAY AND THE UPPER DISTURBANCE
REMAINING SEPARATE.

Therefore, some NWS offices are hanging on to the idea that everything will dry out by Friday. However, an awareness of the other models' opposing views is adding a bit of drama as to how this upcoming weather system will play out.

My thoughts remain the same until I'm convinced otherwise by some type of agreement among all of the models. Even if precipitation should linger in the colder air, the chances of wintry precipitation should be confined to higher elevations of eastern KY. I still think 40's look plausible for highs on Thursday and struggling to get out of the 40's Friday. However, there's still time. Let's see what happens later today with the model runs.

MS

Cold Air Invasion Later This Week

Another piece of cold air is poised to plow through here with plummeting temperatures and plentiful precipitation possible. However, a perplexing piece of the puzzle remains. Any wintry weather working its way from parts of the prairies and pastures of the Canadian provinces?

I've been looking at models, reading other professionals' blogs, digesting information from the National Weather Service offices, and consulting past analogs for the past few days about this upcoming shot of cold air coming our way.

I keep seeing a similar theme. Either the models and analogs are just waiting for more information to digest, or a consistent pattern is developing regarding how this system will unfold.

I don't foresee any wintry precipitation with the models I've been perusing (except in the usual higher elevations of east KY). That still has time to change. The NAM models will now be able to offer some hints. Also, as the storm system pushes closer, the other models should be able to figure this one out, probably by the end of the day or first thing tomorrow.

Although the NWS office here in Louisville continues to advertise high temperatures in the 50's after frontal passage, I still haven't been sold on that thought yet. I think we'll have a difficult time getting out of the 40's one day this week, possibly Thursday. By Friday or so, highs may struggle to reach 50 or 51.

Today, I'll be interested in other NWS offices' thoughts outside of Louisville and read their thoughts about the upcoming week.

In a later post, I'll share some of those with you. In the meantime, have a good one.

MS

Trying To Figure Out the Next System

Another significant storm system to approach the area by midweek next week. One thing I've noticed is that the models I use have 'warmed' over the last few runs. More than likely, there will continue to be fluctuations in the forecast models until a better handle on this over the weekend.

Using historical information by means of analogs, high temperatures will struggle to get out of the 40's for parts of our region. It was looking like low 40's for a few runs. Again, though, fluctuations in strength of the trough and placement/speed will likely occur for the next several runs.

Here's one of the analogs I'm using so far. Bear in mind, as the models make more sense of this upcoming storm, additional analogs will become available for forecast assistance.



















This one is from 2007 around the 20th of November. Therefore, one would have to adjust temps a little bit to fit our late October readings.

So, I can see temperatures here ahead of the front to range between 75 and 80. However, based on this analog, which keeps coming up in these model runs, temperatures will likely crash behind the front by some 30 degrees! Look for highs in many parts of the state to range from 45 to 50 degrees for highs by Thursday/Friday, depending on timing of frontal passage.

As far as wintry precipitation, setup looks somewhat similar to the last system. Not much expected except for the higher elevations in eastern KY. But, this still can change as this storm system evolves

Although severe storm chances appear to be dwindling, I'm not going to write it off completely. There will be some strong wind fields involved. At the very least, there will be gusty winds along and behind the frontal passage. However, severe weather should be confined to the south in parts of Texas, Oklahoma, and Louisiana.

For now, I'll keep looking for trends. Otherwise, we'll just have to wait for the models to decide how best to develop this one. Stay tuned....

MS

...And Now the Next One (also using analogs)

Our recent storm system proved to be quite strong for this time of year, dumping the rain and pumping the cold. At one time, I noticed the barometric pressure reading dropped to 29.04" (983mb) in Toledo OH, good enough for a pressure reading like that of a strong cat 1 hurricane.

While the storm finally winds down, its effects will continue to be felt through Saturday morning with possibly the coldest readings of the season for many before a slow recovery into next week. We could be looking at temperatures reaching the 70's again...ahead of the next storm system.

I still would like to see a few more runs of the GFS. However, I'm starting to pay more attention to the time frame around the 28th of the month for another possible cold invasion. Preceding the cold will showcase ample moisture capable of heavy rains and possible strong storms.

At this time, temperatures look to bottom out in the low 40's for highs by next Friday. However, the shot of cold air looks to be brief. As we head toward the end of the month and into the month of November, I think readings will be quite nice for this time of year.

But, then we'll be talking about the 'next one'.

In my upcoming Winter Weather Forecast 2011/2012, I'll be discussing analog years. For those of you interested in analogs, there is a site that's informative and useful for the cold season. I invite you to check it out here.

MS

MS

Here's a look at the GFS 850 mb map, an area where frozen precipitation can be found before reaching the surface.

The area of 0 degrees C line curls up into central and eastern KY by Thursday morning. However, surface temperatures are expected to stay well above freezing. The amount of moisture still prevalent at the 850 mb level only provides a minimal chance at any wet snowflakes or sleet pellets mixing in at the surface. A little better chance of this at the higher elevations of far east Kentucky, though. Still, not a big issue, only a tease that winter is just around the corner.

During the last hour, I noticed a very large difference in barometric pressure across Kentucky. At 4pm, Covington's barometric reading was at 29.33" while Paducah in western Kentucky's reading was 29.67". Their winds are already gusting to near 30 mph. The same can be said also in Missouri.

During the past hour, the lowest pressure reading that I found was 29.20" at Zanesville OH. That equates to 989 mb. Another reason to expect winds to approach 40 mph as high pressure tries to build in from the west, feeding into the deepening Low.

Expect winds to increase here later tonight especially and on into the day tomorrow. Gusts could top 40 mph at times as the Low continues to deepen to our east and northeast. Wind chill values will be falling perhaps into the 20's and 30's at times. Brrr.

Frost is still looking likely for Saturday morning.

Later in my next post, I'll be looking at the next major weather system to be impacting the region. Already talk of another blast of cold air. We'll break it down and see what's chillin'.

MS

UPDATE Tracking the Beast

Not quite a polar bear system, but it will definitely bring a shock to our senses. Daytime temperatures in the upper 40's and low 50's for Wednesday will feel worse because of gusty winds and leftover rain. Overall, a good chili day. Got mine cooking in the crockpot right now.

Take a look at the cold air...Click on map below.

Click on the map here for a look at Kentucky's temperatures. Quite a constrast setting up.

MS

Lubbock TX Dust Storm

Massive dust cloud moving toward subdivision in Lubbock TX

MS

Tracking the Cold Beast...

Click on the map above to follow the falling temps...

Also, I'll be tracking the 850 mb map, as that shows where the freezing line could set up. Some are forecasting possible wet snow flakes or sleet pellets.

While that's a possibility, one of the latest GFS maps I've been looking at keeps the 32 degree line west of Louisville while areas east will be above 32, again at the 850 mb level or about 5000 feet high.

The Low that will be tracking up the east coast and mountains will bring up some warmer air with it while wrapping colder air behind it, as depicted nicely on this graphic above.

Nevertheless, by Saturday morning, everyone in the region should feel the 'chill of an early fall'

I thought you'd be glad that I told it to you 'Strait'.

MS

One Extreme To Another

I thought you may want to enjoy this weather extreme for yesterday...

Limon, CO municipal apt HIGH 81 / LOW 26
55 degree spread

Here in Louisville, we'll be seeing some extreme temperature contrasts as well this week.
After highs in the low 80's today, possible overnight lows in the upper 20's for some outlying areas later this week.

MS

Keeping An Eye On the Arctic

Within the past couple of days, I've noticed a significant buildup of cold air near the Arctic circle. At one point, I saw a reading of -20 degrees F this morning.

Click map below for a current view of the Arctic chill...

Just a short time ago last week, the temperatures were already falling; however, at least temperatures were near 10 degrees. Therefore, a drop of nearly 30 degrees within the past few days is quite significant.

As daylight continues to fade near the Arctic circle, not much rebound in temperatures is expected. Look for signs of the cold air building south over time. Any number of strong low pressure systems could tap into the 'cold reserve' and sling it southward toward the U.S. border.

MS

October - Known For Large Temperature Spreads

Typically, the month of October is drier than other months of the year, especially around our part of the country. Summer is quickly losing fast hold of its dominance as daylight shortens and nighttime lengthens.

Interestingly, a drier ground can still produce very warm temperatures during the shortening day. However, during the night, the same dryness allows all of that heat to escape back into space thus producing cold readings.

I would like you to check out this site below sometime. The table may not contain all of the U.S. reporting stations, but there is still a lot of useful data.

If you're somewhat knowledgeable of Microsoft's Excel spreadsheet, you can work with the data to find out the highest and lowest temperatures in the table and, one of my favorites, the temperature spread between the highest and lowest temperature of any one location. Of course, you would have to calculate that by inserting an additional column. Then use a VLOOKUP function to find the reporting station(s) that match(es) the largest spread in temperature.

For example, the high and low temperature at Hanksville UT on October 14 was 85 / 35. Therefore a 50-degree spread and one that proved to be the maximum spread of all locations listed in the table.

Here's the link to the table that I'm talking about...Click HERE.

Also, here's a sample of the table I'm talking about...

FILE FORMAT: FIRST RECORD IS DATE IN THE FORM YYYYMMDD. THE REMAINING RECORDS
CONTAIN MAXT(F),MINT(F),REPORTED AND ESTIMATED PRECIP IN HUNDRETHS OF INCHES,
9 WEATHER CHARACTERS,ID AND CITY NAMES WHERE AVAILABLE.
*****NOTE***************NOTE*********************NOTE********************
20111014
30 27 3 3 9SSSF/SRL70026 AK BARROW/W.POST W.ROGERS
39 32 0 0 9////////70104 AK CAPE_LISBURNE(AWOS)
39 35 0 0 9//RRR///70117 AK TIN_CITY_AFS_(AWOS)
36 33 23 23 9R///SSSS70133 AK KOTZEBUE/RALPH WIEN ME
34 29 0 0 9////////70173 AK INDIAN_MTN_AFS_AWOS
35 27 0 0 9SS////SS70174 AK BETTLES
36 32 0 0 9////////70178 AK TANANA/CALHOUN_MEM
36 21 0 0 9////////70194 AK FORT YUKON
44 33 0 0 9RR//////70200 AK NOME
43 36 0 0 9////////70204 AK GAMBELL_(AWOS)
43 34 0 0 9////////70207 AK UNALAKLEET
39 36 0 0 9//M/////70212 AK CAPE_ROMANZOFF_AWOS
41 38 55 55 9RRRRRR//70219 AK BETHEL
36 33 0 1 9RRSSSR/R70222 AK GALENA_AIRPORT
43 34 11 11 9/RRR/RR/70231 AK MCGRATH
48 36 0 0 9////////70232 AK ANIAK
49 40 0 0 9//RR////70235 AK SPARREVOHN_(AWOS)
37 27 0 0 9////////70246 AK MINCHUMINA
37 32 -999 1 9---SS/S-70249 AK PUNTILLA_(LAKE)
41 33 7 7 9R/SSR///70251 AK TALKEETNA
36 34 0 3 9---RRRR-70255 AK SKWENTNA
50 38 11 11 9/RRRR///70259 AK KENAI/MUNI
48 29 0 0 9////////70260 AK NENANA/MUNI
50 21 0 0 9////////70261 AK FAIRBANKS/INTL
49 20 0 0 9////////70265 AK EIELSON_AFB
46 24 1 1 9////////70267 AK BIG DELTA
44 20 1 1 9////////70271 AK GULKANA

The table looks intimidating, but the Excel spreadsheet really cleans it up nicely, making the data easy to work with.

MS

Working On the Winter Forecast 2011/2012 FINAL SEGMENT

Remember these maps above, especially the lower one. Then, I want you to compare all of the winter forecasts made so far with this lower map.

These are typical weather patterns during an El Nino/La Nina winter. But, when was the last time you recall that our weather has been typical? During the past year or so, the United States has endured some extreme weather. Destructive tornadoes, crippling snowstorms, roaring flash floods, extreme drought and heat, just to name a few, have all occurred in one calendar year. I do believe that La Nina conditions will continue to contribute to extreme weather, perhaps here in the United States again.

However, weather does not only happen here in the United States. As I always stress, weather is global. There's not some mysterious jet stream that only exists across the United States, but weather patterns exist all across the globe. How these patterns develop, change, and dissipate can have far-reaching effects.

I want to share a global map of a typical La Nina and its affects.

Just take note of the first map that corresponds to a La Nina winter episode.

Sorry about the map size, interfering with my other blog information on the right side. However, I felt this was an important map to demonstrate.

Looking at data for weather after October 15 2011 suggests to me that our upcoming winter may take on a shape similar to that of winter 2000/2001. A possible significant difference may be that La Nina II may be stronger than the previous one, according to recent reports.

As I will feature in my OFFICIAL Winter Weather Forecast 2011/2012, extreme weather looks to be likely across the globe. Some parts of the United States will see all-time records related to temperatures, snowfall, or rainfall during the upcoming winter of December, January, February, or for the 3-month period.

Which parts of the United States stand the best chance for such records?

Well, I have more data to digest before issuing my official thoughts. I will be considering preliminary data from other parts of the globe at the beginning of November. Then I should be ready for my official forecast.

Look for the MikJournal's Official Winter Weather Forecast 2011/2012 by the end of the first week of November 2011.

MS

Mid-October Report

From my point of view, this has been one of the best stretches of Fall weather in a long time. Warm days and cool nights, clear skies, and dry weather. Everyone who had outdoor activities or chores offered no complaints that I'm aware of. I didn't complain.

Now, turning our attention to a significant pattern change, I'm becoming more convinced that the GFS wants to end the growing season by sometime next week (around Oct 19-20). This could introduce the first sign of how our upcoming winter may play out.

In my final segment on Working On the Winter Forecast 2011/2012, I will show one of the trends that I could be leaning toward, IF this indeed is that pattern change I've been waiting for in October.

At any rate, sometime next week, colder air will be pouring into the Ohio Valley with temperatures tumbling and possible talk about wind chill readings, yes, below freezing wind chill readings. In addition, if enough clearing and calm conditions set in, low temperatures in the city of Louisville could approach the low to mid 30's, meaning that the 'burbs could dip into the upper 20's to low 30's. A killing frost is possible. Stay tuned.

Another shot of cold air may invade the region the week before Halloween. However, I expect warmer conditions before the end of the month.

Looks like how our winter may unfold? Lots of ups and downs....

MS

CPC Changes Its Tune

On Monday, yes, just yesterday, I highlighted the CPC's 8-14 day outlook for Oct 18-24 and it was showing above normal readings for much of our region. Today, a much different picture. Since the GFS introduced the possibility of a significant cold spell for the first part of that period and continues to reemphasize that cold spell, today's 8-14 day outlook paints a much colder solution for the period.

Other teleconnections are supporting this forecast including the NAO, which is forecast to turn negative during this time.

Some of the data I've been looking at supports frozen precipitation as far south as Louisville. Could be wet snowflakes or sleet pellets; regardless, a possible introduction to winter already?

This might prove to be the Season-Altering Pattern Shift (SAPS) that I wanted to see happen during October for finalizing my winter forecast 2011/2012.

MS

Mount Washington Observatory Fall Foilage Picture

What a spectacular view...

Here at my location in Valley Station, some of our trees are already peaking.

MS

Texas - Scorched Land

Since November 2010, over 5625 square miles of Texas land has burned. That equates to a size greater than the state of Connecticut.

Although this figure only represents about 2.1% of the Texas landscape, we can put that into greater perspective. Burned areas represent a drive from Waco to Austin along I-35. From Waco east to Fairfield at I-45. And from Austin northeast to Rockdale at intersection of US 77 and US 79. This is perhaps a little too conservative.

More fires continue despite some recent, beneficial rains in parts of the Lone Star state.

MS

Looking For SAPS (Season-Altering Pattern Shift)

Although the current 8-14 day forecast from the CPC shows our region basking in above normal readings, there are indications of a significant cold spell developing around here by the 18th of the month (next Tuesday). Let's take a look at these current maps:

From the CPC:



Look at the latest GFS model for the 18th of October...

Take note where the '540' line is. That is what we call the freezing line. Yes, I know it's several days out, but the GFS has been somewhat persistent with this feature.

Looks like the cold front that will pass through here later this week, well, its parent Low could get left behind, and spin around near the Hudson Bay area pulling down cold air and funneling that down here in our neck of the woods by early next week.

Will be something to monitor as this could be the Season-Alterning Pattern Shift that I've been waiting for that normally occurs in the month of October. Such a pattern shift could be a signature of what to expect for our upcoming winter.

In just a few days, I'll be presenting my thoughts about some of the locations where our winter could be coming from and what to expect from those locations in my final segment about Working On the Winter Forecast 2011/2012.

MS

Weather News (Drought, Dual Polarization, Winter Weather)

Beneficial rain amounts are affecting parts of northern and northwestern Texas. Doppler estimates of 4-8 inches are showing up in locations from near Wichita Falls (in the north) to Brownwood (in the south) or just to the west of the Dallas/Fort Worth area.

Speaking of heavy rain, south Florida has been soaked during the past 48 hours. Here are some precipitation amounts through Saturday evening: In the Miami area...

LOCATION TOTAL

-------- -----

WEST KENDALL/TAMIAMI AIRPORT 9.22" (ASOS)

PRINCETON 8.62" (SFWMD)

HOMESTEAD GENERAL AIRPORT 7.23" (ASOS)

HOMESTEAD AIR FORCE BASE 5.80" (SFWMD)

MIAMI INTERNATIONAL AIRPORT 5.78" (ASOS)

HOLLYWOOD-NORTH PERRY AIRPORT 5.36" (ASOS)

SWEETWATER (FIU MAIN CAMPUS) 5.05" (NWS MIAMI)

LAKE LUCERNE (NEAR SUNLIFE STADIUM) 4.83" (SFWMD)

As you know, Texas has been in an exceptional drought for a long time. Could the heavy rains impacting parts of the Lone Star state indicate a pattern shift? At the very least, the current storm system will provide some relief..

Parts of east and south Florida have been very dry as well. The current rains there will provide immediate relief. Unfortunately, most of Georgia will miss out on the heavy rains as the hybrid tropical system moves northeast. Some southeastern Georgia counties could see rainfall amounts exceeding an inch, though.

Next, the eventual successor to the current doppler radar is making news this weekend. From the NWS office in Seattle WA, the Dual Polarization technology is being incorporated  as part of an upgrade process for their radars.

The Dual-Pol (as it's often referred) technology has been in the news before, citing claims that this will provide a better 'look' inside a severe thunderstorm, especially the supercellular types that produce tornadoes, even indicating tornado debris signatures. However, there are other benefits as well, as mentioned below:

What are the Potential Benefits of Dual-Pol?

Better estimation of total precipitation

Better estimation of the size distribution of hydrometeors

Improved ability to identify areas of heavy rainfall (flash flooding potential)

Improved detection and mitigation of non-weather echoes

Easier identification of the melting layer (helpful for identifying snow levels in higher terrain)

Ability to classify precipitation type

New severe thunderstorm signatures

More information from the Seattle NWS about Dual-Pol, click HERE.

Finally, for you snow lovers, including yours truly, here is your latest snow depth map. Signs of winter are looking good...click on map below to enlarge.

MS

A Few Thoughts About This La Nina

At this time, we DO NOT have a La Nina at present. However, the Pacific waters are experiencing La Nina conditions that may lead to a La Nina. One must remember that a La Nina is not considered an official La Nina until sea surface temperature anomalies of -0.5 or less are registered for 5 consecutive 3-month periods within the Nino 3.4 region

Year	DJF	JFM	FMA	MAM	AMJ	MJJ	JJA	JAS	ASO	SON	OND	NDJ
2010	1.7	1.5	1.2	0.8	0.3	-0.2	-0.6	-1.0	-1.3	-1.4	-1.4	-1.4
2011	-1.3	-1.2	-0.9	-0.6	-0.2	0.0	0.0	-0.2

Many of the models are nearly split on how the La Nina conditions will progress the rest of the year into next year. The official ensemble mean predicts La Nina conditions to strengthen and continue into the Northern Hemisphere spring 2012.

The La Nina conditions are expected to peak in January or February of 2012 before easing somewhat by May. Forecast anomalies appear to suggest a stronger La Nina for winter 2011/2012 than the previous winter.

Part of my upcoming winter forecast contends that the predicted La Nina will not be as strong as last winter. This is a good reason why I wait and gather all available data before issuing my official winter weather forecast.

I've seen some of the winter forecasts put out there so far. While I admire their input about how the cog of winter's machine will affect regions of the United States, there's just too many variables that have not been considered because those variables simply have not been measured yet.

The closer we get to the month of December, the more reliable the forecast should prove to be. Even at that, statistically, one will not 'nail' the overall forecast.

For those who will rely on whether La Nina will affect the overall pattern for the United States, remember that blocking patterns and cutoff lows could become the main driving force once again for the upcoming winter. Jet stream patterns could prove erratic at times. Remember, also, weather is global. What happens in other countries could affect our weather here. Simply put, looks like another interesting winter of extremes.

In my final segment about working on the winter forecast, I'll be looking at favored locations to look at for weather to become quite interesting in our part of the world. Also, La Nina will have its own input, which will add to the drama. Stay tuned....

MS

Whetting (or Whiteting) Our Appetite

It's exciting to see snow totals like this so early in the season. I hope this is the start of a nice trend:

Several snow reports over 20" according to the snow depth map

I say to keep an eye on this type of weather and see if we get a trend, could be one of those SAPS (season-altering pattern shift) I refer to in my winter weather analysis segments.

MS

Working On The Winter Weather Forecast 2011/2012 PART 3

In part 2 of my segment about the upcoming winter weather forecast for 2011/2012, I looked for the one weather system that would prevail over a season-long weather pattern. I call it SAPS, or Season-Altering Pattern Shift, since the prevailing weather system saps the existing, dominant pattern and forms another one, quite different than the latter.

In addition, there was a second La Nina that had developed during the calendar year 2000. Therefore, I have been trying to find a correlation between the winter of 2000/2001 using the SAPS test and the La Nina II to help figure out how our winter of 2011/2012 might unfold. Indications are pointing toward a second La Nina before the end of calendar year 2011. La Nina conditions are already being reported. Other global features were briefly considered in my last segment that focused on November 2000.

In this segment, I will be introducing those other global features more prominently as I discuss the winter months of December 2000 - February 2001.

First, here's a look at the month of December 2000:

December proved to be a very cold month for a sizable portion of the United States. In fact, Louisville recorded its coldest December on record.

 

DECEMBER	COLDEST
25.0	2000
25.3	1989
26.0	1917
26.6	1876
26.7	1963
28.4	1983
29.1	1935
29.4	1909

Temperatures above reflect the average, taking the high and low temperatures and averaging them for each day to arrive at the monthly average.

Remember the SAPS test, it was an Arctic intrusion that occurred during the November 6-11 time frame. That is what helped set this whole scenario in motion for the months of November and especially December.

 The map below helps really show where the snow fell and stuck around for many:

On a global scale, look at the snow cover frequency map:

Here is a review of the other variables that may have contributed to the overall weather pattern for December:

NAO   (-0.58)

PNA      1.23

AMO  (-0.091)

PDO      0.52

ENSO (Nov/Dec/Jan) La Nina conditions present (-0.7)

One can easily determine the relationship between the NAO and the PNA by analyzing the temperature map above. Negative NAO reflected the ongoing cold pouring out of the northern regions of Canada and the Arctic.

On the other hand, positve PNA reflected ridging in the western U.S., thus warmer temperatures than normal.

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For January 2001:

It appears the persistent ridging in the west began its nudge eastward and helped warm things up a bit for many that endured a brutal December.

However, that didn't stop the overall snowcover from eroding too quickly for our region:

Still, the overall precipitation pattern around our region, especially, showed below normal readings as much of the precipitation track stayed south.

A look at January's variables are provided below:

NAO  0.25

PNA  1.51

AMO (-0.09)

PDO  0.60

ENSO (Dec/Jan/Feb) La Nina conditions (-0.6)

As an interesting side note, the AMO, or the Atlantic Multidecadal Oscillation, is a decades-long pattern of either warm or cold ocean waters relative to normal. We have been in the 'warm' phase for many years now, including 2000 and 2001. However, it was interesting to note that for 4 consecutive months (Oct 2000 - Jan 2001), the AMO was negative. Since we have been in this 'warm' phase, only one other stretch of negative numbers was recorded, and that was in early 2009, which ran from Jan - May.

That year saw La Nina conditions, though not a full-fledge La Nina (must be 5 consecutive 3-month averages of -0.5 Sea Surface Temperature anomalies to be termed a La Nina). For Louisville, nearly 10 inches of snow accumulated for the month of January.

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Finally, February 2001:

This upper air pattern map reflects nicely how temperatures would fare overall for the month.

Warmer temperatures for most of the eastern United States during February, while troughiness brought some below normal readings to the west coast.

Precipitation would average near normal for our region, if not slightly below normal for some.

The snow depth map by the end of the month revealed some interesting data:

And finally, the February 2001 variables:

NAO  0.45

PNA  (-0.16)

AMO  0.08

PDO   0.29

ENSO (Jan/Feb/Mar) La Nina conditions (-0.5); also La Nina official designation

Again, note the NAO/PNA relationship, positive NAO reflected warmer readings across the east, while negative PNA reflected cooler and troughy conditions in the west.

I know this is a lot of data to digest. But here's the kicker. This is only one of several winter patterns that could be studied.

In these past 2 segments, I looked at what I call the Season-Altering Pattern Shift (SAPS). There was an Arctic outbreak that overspread much of the United States during November 2000. Did this set the tone for how the rest of the winter would unfold? What if the SAPS came from a different location, like say the northwest United States? Could this have altered the winter of 2000/2001? Can we definitively say that La Nina conditions caused the Arctic outbreak?

In my next segment, I will introduce other SAPS locations in combination with other past La Ninas and briefly explain what happened during those periods. Hopefully, this will help as I narrow down how our winter of 2011/2012 will proceed.

MS

First Major Winter Storm of the Season to Affect Sierra Nevada's in California

An early winter storm resembling that of an early December snow system will be impacting the Sierra Nevadas in California. Lake Tahoe and Yosemite look to be in line for this first taste of early winter.

Click HERE for webcam shots of the Yosemite Valley....

Here is a projected snowfall map by Wednesday PM.



On this day in weather history...
Saxby Gale of 1869
Read about this by clicking THIS LINK.

On this day...

1927 - First carving begins on Mount Rushmore
1957 - "Leave It To Beaver" airs on CBS-TV
1957- First manmade satellite, Sputnik I, launches into orbit
1976 - Barbara Walters joins Harry Reasoner at anchor desk on ABC Evening News
1986 - Dan Rather mugged by two men in New York City.
1998 - Davis Gaines performs as the Phantom on the Phantom of the Opera for the 2000th time.

October Highlights (Not Really Weather-Related)

Off the beaten path, let's take a look at some of the special days for October and the themes for this month:

Adopt A Shelter Dog Month
Breast Cancer Awareness Month
Computer Learning Month
Cookie Month
Domestic Violence Awareness Month
Eat Country Ham Month
National Diabetes Month
National Pizza Month
National Vegetarian Month
National Popcorn Popping Month
Seafood Month

Here's a selection of some of Mik's Piks for the month:

4th - National Golf Day
5th - Do Something Nice Day
5th - World Teacher's Day
7th - World Smile Day
9th - Fire Prevention Day
11th - Take Your Teddy Bear to Work Day
14th - National Dessert Day
14th - World Egg Day
16th - Bosses Day
16th - Dictionary Day
18th - No Beard Day
22nd - Make A Difference Day
23rd - Mother-In-Law Day
24th - United Nations Day

Looking at this week (Oct 3 - 7), here are some historical notables:

3rd - 1863 - U.S. President Lincoln declared that the last Thursday of November would be recognized as Thanksgiving Day.

3rd - 1954 - "Father Knows Best" began airing on CBS-TV.

3rd - 1955 - "Captain Kangaroo" premiered on CBS-TV.

3rd - 1955 - "The Mickey Mouse Club" premiered on ABC-TV.

3rd - 1961 - "The Dick Van Dyke Show" debuted on CBS-TV.

3rd - 1995 - O.J. Simpson was acquitted of the 1994 murder of Nicole Brown Simpson and Ronald L. Goldman. Simpson was later found liable in a civil trial.

I'll be providing more historical notables for the week in upcoming posts along with a shot of weather tidbits as well.

I'm working on my next segment of Working On The Winter Weather Forecast 2011/2012. That will be released in a few days. I expect to make my official winter weather forecast in early November.

MS