Archive for July, 2009

Saturday’s Rainfall
July 31, 2009

We’ve enjoyed a lot of sunshine for the last day of July; not to mention unseasonably cooler highs in the 80’s.  The unseasonably cool weather will continue into the weekend as showers and storms return.

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The severe weather threat looks low for Saturday.  Storms during the morning into the early afternoon don’t have the sunshine to increase the necessary instability.  The forecasted CAPE values are very low.  The storms for Saturday will be elevated in nature.

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Expect the clouds to roll in during the morning keeping temperatures in the mid to upper 70’s during Saturday afternoon.  The focus for the storms will be a cold front moving out of the northwest.  A few storms may produce very small hail and gusty winds to 40 mph.

General rainfall totals will likely range from 0.25″ to 1.00″.  I wouldn’t be surprised to see totals well over 1.00″ in spots. 

Drew Michaels

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Weather Video Friday
July 31, 2009

Take a look at some of these clips of close lightning strikes. It is big reminder of how dangourus and powerful a single lightning strike can be.

Ross Ellet

July Monthly Weather Wrap Up
July 31, 2009

July is now coming to an end and the weather stats are in…to sum it up in a few words, it was a cool and wet month compared to normal. After an early monthly heat wave an unseasonable cool air mass carved its way into our area and didn’t let go. Here are the monthly stats in detail for both Fort Smith and Fayetteville.

 

 

Statistic Fort Smith
Monthly High 102 degrees
Monthly Low 61 degrees
100+ Degree Days 5 days
90+ Degree Days 19 days
Days Not Reaching 80 Degrees 1 days
Average Temperature 81.6 degrees
Temperature Departure From Normal 0.6 degrees below normal
Monthly Rainfall  4.66″
Rainfall Departure From Normal 1.47″ above normal
Thunderstorm Days 6 days
Monthly Maximum Wind Speed 44 mph on July 4th

 

 

Statistic Fayetteville
Monthly High 98 degrees
Monthly Low 52 degrees
100+ Degree Days 0 days
90+ Degree Days 7 days
Days Not Reaching 80 Degrees 2 days
Average Temperature 75.9 degrees
Temperature Departure From Normal 3.0 degrees below normal
Monthly Rainfall  4.05″
Rainfall Departure From Normal 0.91″ above normal
Thunderstorm Days 8 days
Monthly Maximum Wind Speed 35 mph on July 21st

Ross Ellet

Summer’s Not Done Yet
July 30, 2009

Well you had to know the September like weather couldn’t last forever. The dog days of summer will return and soon…and just like the cool and wet pattern as of late has lasted a couple of weeks so will the sizzling weather. The heat up will begin next week with the worst of it cranking up on Tuesday through Thursday. During this time period the 850 mb temperatures (temperature about a mile above the surface) will approach 27 degrees C (81 degrees F). Temperatures often heat up another 15 to 25 degrees from this point to the ground. This could easily push highs into the mid 90s in northwest Arkansas and around the triple digit mark in the river valley. Below is the 850 mb temperatures for later this week.

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The long range maps are continuing to show the hot conditions. Below is the Climate Prediction Center’s 8 to 14 day forecast. It is calling for above normal temperatures through the first half of August. Late July and early August is typically the hottest time of the year. However this heat wave will likely last through the first week of August and perhaps into the second week of August. However, just like this cool spell we have been seeing as of last, the heat wave will eventually end as well. This leads to an interesting question, could we be entering the last big heat wave of 2009? Or will late August and September continue to pump up the heat?

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Ross Ellet

More Showers & Storms for Saturday
July 30, 2009

Deja vu returns to the forecast.  Today we’ve dealt with a vigorous upper level wave that has sparked off the showers and storms.  Now the computer models are hinting at a similar wave for late Friday night into Saturday morning!

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Here’s the 500 mb flow for Saturday.  I have highlighted the disturbance aloft that will act as the trigger additional rainfall; over an inch of total rainfall is possible! 

If the timing of this wave is during the morning, then the clouds will hold through the afternoon, and temperatures will once again remain in the 70’s!

Drew Michaels

THURSDAY MORNING UPDATE…
July 30, 2009

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There’s still a good chance of some heavy rain in this morning, but the severe threat will be non-existent.  A large cluster of showers and isolated storms are currently moving through Central Oklahoma and heading towards the viewing area for later this morning.  The timing of the rain will be tough due to the fact that these showers and storms have been moving very slowly.  It’s a good bet that near the 7 o’clock hour some moderate rain will be throughout Eastern Oklahoma and moving towards Western Arkansas.  We expect most of the rain to be gone this afternoon.  Here is a look at the latest precipitation forecast.

PRECIPITATION FORECAST (THURSDAY 9 AM)

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PRECIPITATION FORECAST (THURSDAY 12 PM)

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BLOG ENTRY BY: PATRICK CRAWFORD (7-30  4:30 AM)

 

 

Thursday’s October Feel
July 29, 2009

The hottest time of the year climatologically across eastern Oklahoma and western Arkansas takes place between July21st and August 12th.  This is where we average the hottest temperatures of the year.  Here are the averages for the end of July…..

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 It’s hard to believe that Thursday, July 30thwill feel more like October with highs in the 70’s!  The clouds along with lingering showers and storms will help to keep temperatures from warming throughout the day.  The front that will provide the unseasonably cooler air is sitting just to our north. 

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A big warm-up returns to the 7-day forecast, and we’ll blog more about that soon.

Drew Michaels

Tracking Flocks Of Birds On Radar
July 29, 2009

We are in a very busy pattern this week with more heavy rain and strong storms expected overnight tonight and tomorrow, but this morning we are tracking another form of mother nature, birds. Swarms of birds normally take off from their nest around sunrise and spread outward looking for food. Depending on the atmospheric setup these swarms can also be picked up on radar. The birds typically leave their nest every few minutes which creates a solid ring that moves outward from a given location. At first glance of the radar screen near sunrise it may appear a shower has popped up, however with closer observing it becomes obvious something else is going on. Doppler radar commonly picks up flocks of birds in the summer near sunrise, bugs and dust are also other features detected by radar. This morning there was a very large flock of birds detected near Lake Ouachita, and a smaller flock in northwest Arkansas. The flock at Lake Ouachita was moving at about 25 to 30 mph. The smaller flock in northwest Arkansas was moving a little slower at about 20 mph. Here are the radar images early this morning. The time was from 6am to 7am. Each radar image is about 6 minutes apart. Notice the birds highlighted within the red circle.

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bird8

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Ross Ellet

LATEST ON OUR SEVERE WEATHER THREAT
July 29, 2009

We will be under a slight risk of severe weather today and early tomorrow morning.  There will be a threat of very heavy rain, lightning, hail and and some damaging winds.  There will even be a small and I stress small tornado threat in Southeast Oklahoma.  Here is a look at the latest update on our severe weather chances:

SEVERE WEATHER RISK (WED AM – THU AM)

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HAIL THREAT (WED AM – THU AM)

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WIND THREAT (WED AM – THU AM)

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TORNADO THREAT (WED AM – THU AM)

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Notice how the tornado threat is extremely low, but it’s definitely worth a mention.  Now the biggest threat that we have been focusing on for the past several days will be the heavy rain.  Here is a look at the latest rainfall estimates throughout Wednesday and early Thursday.

6 HOUR RAINFALL ESTIMATE (WEDNESDAY 7AM-1PM)

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6 HOUR RAINFALL ESTIMATE (WEDNESDAY 1PM-7PM)

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6 HOUR RAINFALL ESTIMATE (WED 7PM- THU 1AM)

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6 HOUR RAINFALL ESTIMATE (THURSDAY 1AM-7AM )

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6 HOUR RAINFALL ESTIMATE (THURSDAY 7AM-1PM)

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BLOG ENTRY BY: PATRICK CRAWFORD (7-29  6:15 AM)

Heavy Rainfall & Storms…..
July 28, 2009

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The computer models have been targeting a very heavy rainfall event for late Wednesday night into Thursday morning.  A strong upper level wave moving out of the northwest will act as a trigger for overnight showers and storms for Thursday morning.

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This cold front above will drape itself across the area on Wednesday.  This front will serve as the focus for the nocturnal showers and storms for Thursday morning.  The complex of storms that develops in Kansas will follow the front into our area.

When it’s all said and done, the area can expect between 1 to 2 inches of total rainfall by Thursday afternoon.  Some spots may pick up over 3 inches.  Severe weather may accompany the leading  edge of the showers and storms.  Gusty winds to 60 mph and small hail are often common with these complexes. 

Expect the lingering showers and storms to end around noon on Thursday.  The sky should start to clear by Thursday afternoon; however, temperatures will likely remain in the 70’s!  Low clouds and fog will redevelop by early Friday morning thanks to the heavy rainfall.

Drew Michaels