Thursday, August 8, 2013

What Are Louisville's Rain Chances?

So far, it's been a guessing game as to when Louisville will see measurable rain. Today, I'm seeing that window shrink. Radar looks like a ring of water around Louisville.

Infrared satellite has been showing warming clouds west of the area and a gradual weakening of its associated complex. However, am starting to see additional convection firing out toward Paducah. These are beginning to form an outflow line of storms that should take over the rest of the afternoon as it moves east.

The bulk of the storms may stay just south of Louisville. But, our chances of getting wet are increasing. One of the short-term models is showing precipitation breaking out near our area after midnight.

Rain may be heavy as evidenced by parts of the Bluegrass region who got swamped last evening.

MS

Monday, August 5, 2013

Wet Week Ahead? (Aug 5-12)

A change in the weather pattern is in store for the region this week. A persistent northwest flow has dominated most of our summer, but the atmospheric pattern will change to a more zonal flow (w to e) this week.

A large fetch of moisture is forecast to impact the region by the middle of the week. Depending on the front's position, periods of heavy rain could set up for some. Widespread 2-3" amounts are expected this week.

A caveat is in the front's position. While the WPC paints widespread amounts, it must be understood that the potential exists for these amounts if any disturbances interact with the slow-moving or stalled front and its favored location.

Heaviest rains at this time appear to reside south of the Louisville area. However, until a better understanding about where the front will be located the next few days, it's more of a guess than a forecast.

If heavy rains do materialize, some areas in our region will have to worry about flooding concerns.

MS

MikeS 66 Index JULY 2013

The official statistics are not out yet for the month of July. However, my index of 66 random locations comprising the various climate regions of the contiguous United States revealed some interesting data.

It was a month dominated by persistent weather patterns. A large ridge in the west. A cutoff low in the Gulf of Mexico. A large upper level low spinning across the Hudson Bay. A bulging southeast ridge. Sometimes, it was a matter of the have's and have not's, especially when it came to precipitation.

Overall, the temperatures averaged out right at normal. However, the overall precipitation came in well above normal. Four of the six climate regions produced above normal readings with the southeastern U.S. coming in with some of the wettest July's in years. This was due to a persistent onshore flow of moisture resulting from a stationary non-tropical low spinning just south of the Florida panhandle.

Now for the numbers...

High Plains 73.4 average of high and low
                                    0.4 Below Normal (temps)
                                    14% Below Normal Precipitation

Midwest  72.3
                              0.3 Below Normal
                              25.8% Above Normal Precipitation

Northeast  75.8
                                 2.2 Above Normal
                                 25.8% Above Normal Precipitation

Southeast  80.0
                      1.2 Below Normal
                                 64.3% Above Normal Precipitation

Southern   80.9
                      1.2 Below Normal
                                 3% Above Normal Precipitation

West         77.1
                     1.7 Above Normal
                               13.7% Below Normal Precipitation

You can tell how the western ridge affected temperatures and precipitation there. Extreme heat prevailed over much of the desert areas. Also, the persistent upper low in the Gulf produced enormous amounts of rain. What I found staggering about those numbers was that normal rainfall amounts start ramping up during tropical weather season. In fact, places like Tampa FL and Wilmington NC generally see at least 7" on average for the month of July. Although Tampa exceeded their average, Wilmington's 5.64" for the month was a stunning 1.84" below normal! There were no tropical systems in July that directly affected the U.S. but many locations added to their June totals making inroads on one of the wettest summers on record.

As for the Northeast, I was there when temperatures soared well into the 90's and touched 100 in a few areas. The dew point was high adding to the discomfort. Power outages occurred. Children often flocked to fire hydrants to keep cool. Some of the places I visited were running on generators just to cut down on the high energy demands.

Here's the final tally for the United States as a whole:

United States (48 contiguous) 76.6
                                  0.0 Average
                                        14.2% Above Average Precipitation

MS

MikJournal Midweek 11/16/2017... A Lot of Data

Good afternoon. My expected midweek post was a little bit delayed. I had an influx of data to pore over and did not have time to write ...