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Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Tue Feb 06, 2018 8:04 am
by srainhoutx
We need to monitor the weekend sensible weather forecast very carefully. The Global models are still resolving that Polar Vortex Split and the Sudden Stratospheric Warming Event that will be under way this weekend. Very cold air lurks across the Central and Southern Plains where temperatures are in the single digits to lower teens this morning. Tomorrow and Thursday is probably going to feel rather chilly with temperatures struggling to get to the lower 50's at best. The next spoke (Arctic Front) dropping S out of Canada is rather frigid with another spoke (Arctic Front) arriving Sunday. That Hudson Bay Polar Vortex continues to spin and pull down very chilly air from Canada into the Plains. The images below show the Upper Air (500mb) pattern with a NW flow and a cross Polar flow into the Day 8+ period. The other image is the SSW (Sudden Stratospheric Warming) Event underway. Those events are not uncommon, but do not happen very often. The last SSW events was in 2012 and another in 2009. We are still try to understand the full implications of these events that pull extremely cold air from the Troposphere down to the surface, although moderated. Some of the best Forecasting minds are advising caution when attempting to accurately forecast what the long range forecast may bring regarding our sensible weather, so take that into consideration.

Temperature forecasts for the weekend look particularly dicey, even for SE Texas. As Jeff mentioned in his morning update, that freezing line may be across our Northern Areas while precipitation is falling. That is based off the overnight guidance. If the temperatures are colder than expected as we are seeing some of the NWS Forecasters in Ft Worth/Dallas hinting, that freezing line may near the Northern suburbs of Metro Houston.

I still believe that the end of February into early March has a surprise or two before week transition into a more zonal flow and Spring like temperatures.

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Tue Feb 06, 2018 10:51 am
by Texaspirate11
AFTER this very cold winter, I'm hoping for a very quiet cane season...just hoping out loud....

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Tue Feb 06, 2018 1:24 pm
by christinac2016
I'm hoping whatever little "surprises" are left come before end of February into early March. I'm in the Woodlands Half on 3/3 and don't particularly want to walk/run in freezing temps for 13.1 miles.

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Tue Feb 06, 2018 2:24 pm
by srainhoutx
guidance of tonight into tomorrow suggest the risk of thunderstorms capable of producing very small hail has increased a bit closer to Houston and extends East to near New Orleans, The cold frontal boundary is nearing the Hill Country and should continue to push S overnight. A glance at the last 12Z guidance suggest we may need to trim back expected high temperatures a bit tomorrow. It likely we will not escape the 40's. It's currently in the mid 70's behind the warm front here in NW Harris County. Tomorrow will feel raw compared to today.
02062018 20Z day1otlk_20180206_2000_prt.gif
A quick look at the weekend and the last data from the various computer schemes also suggest a lot of uncertainty. The GFS continues to be about 12 hours slower with the front not arriving until Sunday night while the rest of the guidance has the front arriving during the morning/midday hours on Sunday, depending on the guidance you choose. Temperatures behind the front spread from the 30's to the low/mid 40's for Sunday highs except for the GFS which has near 70F. Overnight temperatures flirt with freezing mainly across our Northern Areas from College Station to Huntsville to Lake Livingston...generally.

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Tue Feb 06, 2018 5:39 pm
by jasons2k
And just like a light switch, the elms and maples are already blooming out! That means I need to prune my oaks this weekend!

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Tue Feb 06, 2018 5:58 pm
by DoctorMu
Texaspirate11 wrote:AFTER this very cold winter, I'm hoping for a very quiet cane season...just hoping out loud....
Year of the Shear! Fingers crossed.


As srain discussed, we're in quite the opposite of a zonal flow...kinda spiky. I'd rather Alaska release the hounds and give us 38°F and sunny rather than 48°F and rainy. Volatile and uncertain temps Wed night and Sunday. Could be freezing...or not. Certainly, a lot of clouds and overrun. Hopefully, everyone can avoid that flu bug, whether you've had shots or not!

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Tue Feb 06, 2018 9:57 pm
by jasons2k
The front went through here at 9pm. Temp has dropped from 71 to 61 in the last hour. Y’all already know how I feel about that ;)

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Tue Feb 06, 2018 10:37 pm
by DoctorMu
:lol: Thundersnow in Greenville, TX just east of Dallas. Wet and chilly night with the 30s hovering near Marlin.

Every day may bring a surprise in the near future.

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Tue Feb 06, 2018 10:39 pm
by DoctorMu
jasons wrote:The front went through here at 9pm. Temp has dropped from 71 to 61 in the last hour. Y’all already know how I feel about that ;)
About 20° colder here in CLL. You'd be freaking out.


We're going to see some wild temp gradients in the next few days.

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Wed Feb 07, 2018 5:30 am
by Katdaddy
Back to Winter for a day with more blah weather. The cold front is moving off the coast this morning with mid to upper 40s across most of SE TX and some upper 30s inland. An upper level trough and SW flow aloft will continue the development of scattered to numerous showers and a few thunderstorms across SE TX today. Radar is becoming more active across Central, S Central, and SE TX currently. A slow warming trend and some partly cloudy skies ahead of the next upper trough which will result in a wet weekend and another cold front. I am ready for the sunny and 80F Spring days.

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Wed Feb 07, 2018 7:19 am
by srainhoutx
Seeing reports of pea sized hail with the band of elevated thunderstorms moving across our area this morning.

Image

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Wed Feb 07, 2018 7:51 am
by srainhoutx
A quick look ahead toward the weekend and next week, the progressive roller coaster pattern looks to continue with spokes of modified Arctic Air arriving every 3 to 4 days with a very noisy sub tropical jet overhead. I don't expect to see much if any sunshine throughout the next 8 days or so. Fog and chances of rain as well as some storms possible with each frontal passage (Sunday/next Wednesday/Following Saturday). I know I am sick of the dreary February weather, but from what I am seeing into the extended range there isn't much of a chance for this pesky pattern to relax as we head toward the end of February. The guidance suggest we enter Phase 8 with the MJO, a -AO/+PNA/-NOA regime appears to be growing in possibilities with general storminess and shots of entrenched cold air along and East of the Rockies developing post SSW event around Mid month. Come on Springtime!

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Wed Feb 07, 2018 9:54 am
by jasons2k
Be thankful for the rain. Much of Texas and the US is under dry or drought conditions. We are (for a change) one of the pockets not painted on the map. We are very fortunate in that regard. Now if we could just keep the freezes at bay....my plants are trying to bloom already.

http://droughtmonitor.unl.edu/

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Wed Feb 07, 2018 11:48 am
by DoctorMu
It was 36°F and thunder this morning IMBY. 39°F now with more dark clouds, thunder. Quite some LIFT in this system!

Some patch wintry mix rolled through Waco, but nothing of interest for our area yet.

As Srain, indicated...more of the same up and down foggy, cloudy, rainy craziness for the next 8 days. We had fog last night with 15-20 mph winds - pretty unusual, but it's Texas weather.

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Wed Feb 07, 2018 12:13 pm
by jasons2k
Looks like another round may be on the way this afternoon.

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Wed Feb 07, 2018 12:37 pm
by Electric Lizard
A quick lived storm produced pea sized hail here in Greenvine (SW Washington County). Let me tell you that even very small hail is VERY LOUD in a metal barndominium.

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Wed Feb 07, 2018 2:05 pm
by Ounce
My, my! Don't remember getting too many intense thunder action cells before Valentine's Day, in past years.

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Wed Feb 07, 2018 4:13 pm
by texoz
In geographic terms, I drove from Austin to Houston and back to Austin yesterday (Tuesday) between 10am and 7pm.

It meteorological terms, I drove from 46 degrees with light showers then through fog & moderate showers around halfway, and then finally arrived at party cloudy and 74 degrees. Then the reverse back to ATX after a few hours in Houston.

I've done that drive 100s of times over the years and that was definitely one of the more interesting ones.

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Thu Feb 08, 2018 2:50 am
by srainhoutx
I continue to see a lot of volatility in the various Ensemble schemes regarding the weekend and next sensible weather forecast. For example the 00Z ECMWF EPS has done a 180 flip from its previous solutions suggesting a deep cold trough to our West and a Blocking Alaska PNA Ridge. That suggests cold air flooding Western Canada and the Western 2/3rds of the US. I believe the various computer schemes are struggling with the Sudden Stratospheric Warning event and further gives pause to being very cautious beyond a couple of days regarding what the weekend temperature and precipitation forecast may bring extending into next week. Past experience suggests that when we see a major Northern Hemispheric Pattern reshuffle such as the current PV split/SSW event, the computer models struggle attempting to resolve these major pattern changes.

Re: FEBRUARY 2018 - Very Progressive Pattern/Roller Coaster

Posted: Thu Feb 08, 2018 3:15 am
by DoctorMu
Canadian has wintry mix action around the Hill Country Sunday - Monday. Euro running pretty cold then. Another cold surge possible around the 20th. Early this morning to sink towards the freezing point in CLL and northern counties.