Monday 9/24 Update

Hello everyone, hope you stayed warm this morning!  For the second straight day, we had an official low of 38 degrees at Barkley Regional Airport.  But after a chilly start to the day, our focus for this week is actually on a setup that will lead to unseasonable warmth and a lengthy period of shower chances.

Looking ahead to tomorrow, we'll have a warm front lifting into the region.  Ahead of this front, moisture is increasing, leading to the arrival of some higher clouds this evening.  After midnight, chances for scattered showers and imbedded rumbles of thunder will be arriving. Along with rain chances, this front will also bring in some very warm and humid air. A very noticeable warm up will accompany this front as well, with highs expected in the mid and possibly upper 80's tomorrow!  As the warm front lifts into the region, the cold front pictured from near Chicago back into Iowa and Nebraska will slide south and stall across our region.

The stalled front will be keeping our weather setup fairly unsettled through the week.  The GFS surface chart above shows shower chances arriving by early Tuesday, and continuing along the stalled front through Wednesday morning.

And a glance at the model from Wednesday PM through Friday AM continue to show a band of purple draped across our region...indicating continuing chances for rain near the front through the end of the week.

As we look ahead to the next several days on the surface map above (top left shows Thursday, top middle Friday, etc), it looks like this frontal boundary will be part of our weather picture through the end of the week, until another front over the weekend is able to win out and push some cooler and drier air south.  Before that next front arrives on Friday or Saturday, we'll have about a 30% chance of rain each day...with the highest chances along/north of the Ohio River.  Temperatures will stay quite warm south of the front as well, with highs running in the mid 80's through Thursday.

The forecast models have been a bit of a jumbled mess for late in the weekend and the first of next week, so I'm not going to get into much there until we have a little better model agreement.  Hopefully we can keep it dry for BBQ on the River!

Tuesday 9/18 Update

Good Tuesday!  Hope you've had a chance to step outside for a bit and enjoy a little of today's fantastic weather.  I think it's safe to say that there is a fall feel to the air today.  The main issue in the forecast for the short term is how chilly it gets tonight...so here's a chance to learn a bit more on the challenges of forecasting temperatures.  Normally, we'll start with a check of the forecast model guidance to see what they are suggesting...for tonight, one model (GFS) shows 41...the other (NAM) is a tad milder at 44.  Another factor we look at are sky conditions....with clear skies tonight, things will cool down pretty quickly as the solar radiation from the sunlight today escapes back into space (clouds typically work to "blanket" the atmosphere, keeping some of that solar energy trapped & temps slightly milder).  The main factor we'll need to examine tonight is the dew point.  Temperatures cannot drop below the dew point (unless water vapor is condensed out), thus the dew point gives us a good idea of the absolute chilliest it will get.  The dew point this afternoon is not quite as low as expected, and with high pressure settling in and winds going calm tonight, the dew point will level off.  Neither model is showing dew points dropping lower than 40, so this is a pretty good indication that overnight lows will not be dropping below 40.  It does look like our record low of 41 is in serious jeopardy though.  Regardless of whether it's 39 or 42, it's still going to be a chilly night!  Just wanted to offer some insight about the complexities of forecasting.

Moving on...with high pressure parked over the region, things will be very quiet for the next couple of days.  With plenty of sunshine, we'll see a return to the mid 70's tomorrow, upper 40's Wed. night, and back to around 80 on Thursday.

By Friday morning, our next cold front will be entering the area from the west.  Models are still showing this system will bring a slight chance of rain....but not much. Here's the European model's 6-hr precip at 1PM Friday:

The GFS 6-hr precip is just a tad later in the day, but equally unimpressive:

There has been a little model disagreement on how fast this front will move through. Some push it on through by early Saturday, while other runs have the front slowing down and lingering over eastern parts of the area early Saturday.  If it hangs up, things could be a little cloudy on Saturday...a quicker progression of the front would mean more sunshine.  Either way, it will be a pleasant weekend, with highs in the low/mid 70's, lows in the mid 40's.  

Finally, a look ahead to next week, the story will be a return to average or above average temperatures.  As seen on the 850 mb chart (temperatures) above....we'll return to more of a southwest flow pattern, allowing warmer air to move back in. Early indications are the most of the week will feature highs in the low/mid 80's.

Monday 9/17 Update

As expected, it's been a gloomy and showery Monday.  The heaviest rains have stayed south of I-40, although there have been a few localized spots that have picked up around an inch or so.  We'll continue to deal with a chance of showers and thunderstorms tonight, before a potent cold front sweeps through the area.  By 7AM tomorrow, the front will be through the area, bringing an end to rain chances:

Behind this front, the coolest air we've seen since last spring will come pouring in.....with temperatures struggling to get out of the 60's tomorrow.

As this cooler air moves in, we'll have some pretty stiff NNW winds to deal with.  15-20 mph winds will be common, with gusts 25-30 mph possible.  The NWS has issued a Lake Wind Advisory for Tuesday.

Tomorrow night we could be talking about record lows.  Forecast model guidance is showing 39 (NAM) & 42 (GFS) for overnight lows.  We should have optimum conditions for radiational cooling, with clear skies and light winds, so I certainly wouldn't be surprised if the upper 30's panned out.  The record low for Paducah on Wednesday morning is 41...the record for Cape Girardeau is 40.  If we did drop to 39 or lower tomorrow night, it would be the earliest occurrence of 30's in Paducah (by 2 days).

Sunshine returns for Wednesday and Thursday, helping temperatures warm up closer to normal (Avg high 82/ avg low 58).  We'll remain below average through the week because of a big trough over the Great Lakes region:

By Friday, the next cold front will be knocking on our door:

This front will be a little slower, and won't have much moisture or upper-level energy to work will, so while we'll have small rain chances in the forecast for Friday & Saturday, the more significant rain will stay to our north.  Like tonight's front, this one will also pack a pretty good punch, with more chilly air set to pour in for the weekend:

Looks like highs will be staying in the lower 70's for the weekend, with lows in the low/mid 40's.  All of this just in time for the arrival of fall at 9:49AM Saturday!

Friday 9/14 Update

Happy TGIF!  We are headed into the last weekend of summer (fall arrives next Sat. at 9:49 AM)....but this weekend will feel plenty like fall.  The forecast is a little bit of a headache for this weekend, so let's jump in.

We'll jump ahead in the charts to Sunday at 7PM.  Above is the 500 mb chart (upper air chart...about 18,000 ft), where we keep an eye out for those "mid-level disturbances" you may sometimes here us talk about.  We find a rather elongated disturbance running from Texas, northeast across Arkansas, and into our area (look for shades of light blue/green/yellow...indicating "vorticity", or spin).  Ahead of this disturbance, southwest flow aloft will keep moist air from the Gulf of Mexico streaming toward our region, and this disturbance will keep considerable cloud cover over our area for most of the weekend.  This will keep daytime highs in the mid 70's, about 5-10 degrees below normal for this time of year.  Lows will run in the mid 50's.

As that disturbance moves east across the deep south, it will lead to some rain chances for the southern half of the area.  Right now, it looks like the best chances arrive later Sunday night/early Monday....however, models have been trending a little quicker with this system, something to watch. Rain chances may have to be bumped to an earlier time frame if this trend continues, and if this system tracks farther north, it may lead to a showery Sunday. With models not yet seeming to have a good handle on this system, it makes at least the Sunday forecast a little uncertain. 

Just as that mid-level disturbance begins to wind down, a fairly potent cold front will be knocking on our door from the west on Monday.  This will lead to our best chance of rain area wide, as seen on the Monday 7PM chart below.

With rain chances ending by Tuesday morning, the end result should be slightly heavier rain across the southern half of the area...with totals running from around 0.25" north, to possibly around 1" south.  These numbers could certainly change with upcoming model runs though.

After the rain moves out, the bigger story with this system is going to be the arrival of a brief, but significant shot of cooler air, as seen on this 850 mb chart for 7AM Tuesday (lower-level chart, about 5,000 ft....used to analyze temperature trends):

Those "cooler" colors in shades of green/blue represent a batch of cooler air that should ultimately lead to highs in the upper 60's/near 70 on Tuesday, and lows Wednesday morning in the mid 40's! If that's too cool for you, this little dip in the jet stream will swing on through and we'll at least get closer to normal for the end of the week.

By the end of the week, it looks like another cold front will be sliding closer to the region, with perhaps another chance of rain.  With that still nearly a week away, we'll save the details for that system for the next update over the weekend.  Hope you enjoy these pleasant temperatures this weekend!

Wednesday 9/12 Update

Hello again everyone!  The blog is back after a few days on vacation in the Sunshine State.  It seems that we have turned the corner and are starting to head into that transitional time of the year when the days grow a little shorter and the temperatures gradually get a little cooler.  That at least seems to be the trend as we look ahead to the next week or so.

We'll continue with pretty standard conditions over the next day or so, with lows tonight headed back to the lower 60's, and highs tomorrow back in the mid 80's.  Like today, tomorrow will feature a decent amount of cloud cover scattered among some peaks of sunshine.  By tomorrow night, the next weather system to move through the area will be knocking on our door from the northwest.

This is the surface map at 7PM Thursday, depicting a cold front running from southern Michigan all the way down through Texas.  This front will be heading into the Local 6 area by Friday morning, but as it progresses on to the east, the amount of moisture it has to work with will be in short supply.  Here's what a couple of the forecast models are cranking out on Friday...

GFS 6-hr precip through 7AM Friday:

GFS 6-hr precip through 7PM Friday:

European model 6-hr precip through 7AM Friday:

European model 6-hr precip through 7PM Friday:

As you can see, there isn't much rain to be found over our area.  So, while we'll have to deal with a mainly cloudy day, and perhaps a few spotty light rain showers, it looks like measurable rain is going to be hard to come by.  Today at midday I said I'd be surprised if many of us picked up more than 0.1" of rain.  While we need more rain to continue making up ground on our drought, this forecast is good news for football coaches that are probably getting tired of seeing rain in the Friday night forecast.

Behind this front, it looks like a fantastic Saturday, with mainly sunny skies, highs in the upper 70's, and lows in the mid 50's!

Things get a little trickier in the forecast for Sunday-Tuesday.  Models have been showing a mid-level system moving in from the west sometime during that time period, but there hasn't been much model agreement on the timing, location, or effects from this.  So until we get better run-to-run consistency, the forecast will include some clouds and a very small rain chance...but we'll have to take a wait-and-see approach.

The medium-range GFS shows a more substantial cold front sliding through next Tuesday, with another rain chance and at least a brief shot of even cooler air:

GFS 6-hr precip through 7AM Tuesday 9/18:

This system probably won't be a big rain-maker, but it does look like it could bring a pretty significant blast of cooler air:

GFS surface temps 7AM Wed 9/19:

In case it's a little difficult to decipher what you are seeing, those shades of green over the Local 6 area are temperatures in the upper 40's by Wednesday morning!  Keep in mind, models can change over the span of a week, but this will be something to watch. 

No update on Thursday, but the blog will return Friday with more updates!

Wednesday 9/5 Update

Scattered showers and thunderstorms are on tap this afternoon....thus, this will be a pretty brief update.  A Severe Thunderstorm Watch remains in effect for a large portion of the region today:

With any storms that develop this afternoon/evening, the primary threat will be large hail/damaging wind gusts. 

After today's action, our next round is still on tap for Friday & Saturday.  Models are still in very good agreement on a cold front passing through the region, bringing a good chance of widespread showers and storms. 

By 7PM Friday night, the front will be bisecting the region...probably leading to some wet weather for Friday night football. Here's a snapshot of what the forecast models are showing:

GFS 6-hr precip at 1AM Saturday:

European model 6-hr precip at 1AM Saturday:

Should be a decent rainfall event, with latest HPC forecast showing around 1" for most of the region:

Models were flip-flopping over the past couple of days with whether or not this system would move on through or hang up to our east as a closed low....but today it seems they have come into agreement on a more progressive solution that pushes this system to our east by Sunday.  This will bring a dry end to the weekend, and some very pleasant temperatures as well.

(A little R &R time on the way for TO, so the blog will return Tue 9/11.)

Tuesday 9/4 Update

Good Tuesday afternoon!  Yesterday marked the "unofficial" end to summer with the Labor Day holiday....but the heat and humidity keep marching on.  A very typical late summer afternoon across the area, as evidenced by this view from the Wastepath Skytracker from U.S. Bank in downtown Paducah:

With dew points running well into the 70's today, heat index values are in the upper 90's to around 100, especially where sunshine is most plentiful. That will most likely be the case again tomorrow, as least in sunnier spots.  However, some fall-like changes are just a few days away....with both cooler temperatures and rain chances in the forecast.  We'll take all the rain we can get, because even with the help we received from Isaac, we are still running over 14" below average in Paducah & Cape Girardeau!

The first system is still set to move in tomorrow.  The image above shows an area of lift moving across central MO tomorrow afternoon (shown in the shades of green/yellow/orange).  This will help tap into the tropical moisture in place to generate some scattered showers and thunderstorms.  This is not the most potent of systems, so coverage will most likely be fairly low.  The best time frame for precip will be in the afternoon/evening hours...but something as early as tomorrow morning can't be ruled out.  Rainfall totals should be pretty low....aside from a localized heavy downpour, I'd be surprised to see much more than a quarter of an inch.

The second system to bring rain chances to the area will be a bit more potent.  A cold front will arrive on Friday...with a surface low along the front out in the Plains Friday morning moving northeast along the front and through our area Friday night/early Saturday.  While chances for showers and thunderstorms will be in the forecast as early as Friday morning, it looks like Friday night and Saturday morning will be the best chance for wet weather.  Models look to be in pretty good agreement at this point.

GFS 6-hr precip at 7AM Saturday:

European model 6-hr precip at 7AM Saturday:

This system should pack a little more punch, and hopefully deliver another decent rain.  The latest HPC 5-day rainfall forecast shows most of the region picking up somewhere in the neighborhood of an inch of rain through the weekend:

 

Starting Sunday, the models diverge on what happens to this system.  The European model is more progressive and goes ahead and pushes this system on to our east:

 Meanwhile, the GFS is wanting to develop it into a closed low to our east:

If the Euro is correct, we'd most likely get back to sunny skies for Sunday and Monday.  If the GFS solution wins out, then things would be slower to clear off, and we may even have a few lingering showers in the eastern sections of the area on Sunday.  We'll have to see what the models do with this over the next couple of days.  Either way, some very pleasant air is set to arrive for the weekend.  Still looks like highs in the upper 70's/low 80's, and overnight lows in the 50's starting Saturday.  We'll take it!

Monday 9/3 Update

Happy Labor Day everyone!  Hopefully the overcast skies and scattered showers haven't dampened your plans too badly.  After enjoying an extended Labor Day weekend (with a little interruption from severe weather Saturday night), it's time for a post-Isaac blog update. With all of the Issac-related maps and charts posted last week, I'm going to keep this one pretty short and sweet.

With things wrapping up with Isaac, I am pleased with the forecast we went with, and how things turned out.  You'll remember we finally settled with a rainfall forecast of 1-2" across KY & TN, 2-4" across IL & MO, with locally higher totals near stronger storms.  Here are the rainfall totals I was able to come up with across the area for this event:

NWS totals:
Poplar Bluff: 6.40"
Mt. Vernon: 5.88"
Carbondale: 4.98"
Providence:  2.64"
Cape Girardeau: 2.42"
Paducah: 2.29"
Farmington: 1.88"
Hopkinsville (Ft. Campbell): 1.37"
Dyersburg: 0.47"

KY Mesonet totals:
Morganfield:  3.19"
Marion: 2.43"
Draffenville: 2.41"
Mayfield: 1.71"
Hickman: 1.63"
Earlington: 1.42"
Murray: 1.21"
Princeton: 1.14"
Cadiz:  1.12"

Isaac will be slowly moving east and fizzling away tomorrow, which means sunshine will return.  With that sunshine, along with lots of tropical moisture left behind, it should get quite steamy.  Highs will run in the upper 80's to lower 90's, but we could see some triple-digit heat index values, especially in SEMO & TN.

A fairly weak mid-level shortwave moves in on Wednesday, possibly leading to a few showers and thunderstorms....although it doesn't look to be a very potent system.

 By Friday morning, we'll have a frontal boundary draped across the area, with a surface low developing across the Central Plains.  That low will move northeast along the front, leading to a good chance of showers and storms Friday and Saturday.  Could be a couple of strong storms Friday afternoon/evening, depending on how much sunshine/instability we have. 

Models are split with what happens to this system in the Sunday/Monday time frame.  The GFS model slides it on to our east pretty quickly, bringing in dry air and sunshine....while the European model develops this into a closed low, keeping considerable cloud cover across the region.  Regardless, some cooler air will arrive by Saturday, with highs possibly dropping as low as the mid/upper 70's, while lows look to be headed toward the mid/upper 50's.  More details on all of this tomorrow.