Texas Spring 2016

[South Texas Storms]

Yeah it's actually showing the upper-level low stalling over Texas, which brings back wrap around precipitation to south central Texas. The 12z CMC is showing a similar solution as well.

[wxman57]

Euro is more progressive with the upper trof, and it's been beating the heck out of the GFS lately. Still, it shows a slower-moving trof than it did before. Better chance for more rain across east TX.

[TheProfessor]

The 12Z GFS moves the low pressure northeast away from Texas, then loops it back around to the northwest to near Austin. The rain totals went up substantially as a result of that.
[img]http://www.tropicaltidbits.com/analysis/models/gfs/2016030212/gfs_mslp_pcpn_frzn_us_36.png
[img]http://www.tropicaltidbits.com/analysis/models/gfs/2016030212/gfs_apcpn_us_40.png

That looks more like a snowfall map lol, is that 24 inches of rain I'm seeing near the Mississippi river? That could cause some very bad flooding along the river.

[Ntxw]

Yeah what the models showing essentially is a boundary or "highway" for rain and storms to form under SW aloft ahead of the storm moving N/NE/E and then wrap around rain once the actual ULL ejects slowly out of the SW. In the warmer seasons its the same set up for heavy rain but instead of ULL to our SW its usually an EPAC storm. Physics are similar.

[cheezyWXguy]

Yeah what the models showing essentially is a boundary or "highway" for rain and storms to form under SW aloft ahead of the storm moving N/NE/E and then wrap around rain once the actual ULL ejects slowly out of the SW. In the warmer seasons its the same set up for heavy run but instead of ULL to our SW its usually an EPAC storm. Physics are similar.

What does this suggest in terms of severe potential next week?

[wxman57]

That looks more like a snowfall map lol, is that 24 inches of rain I'm seeing near the Mississippi river? That could cause some very bad flooding along the river.

That's about 16" of rain over eastern Arkansas on the 12Z GFS. 12Z EC has about 12" of rain about 100 miles west of that area, right across central Arkansas.

[weatherdude1108]

EWX is favoring the ECM over the GFS, because they said it makes more sense than the GFS.

FWD is favoring the GFS, discussing about how the ECM was being too fast in ejecting the low out of Mexico eastward.


FXUS64 KEWX 022117
AFDEWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
317 PM CST WED MAR 2 2016

.LONG TERM (FRIDAY THROUGH WEDNESDAY)...
FRIDAY INTO THE UPCOMING WEEKEND...EXPECT THE RETURN OF SOUTHERLY
FLOW...CLOUDS AND MAXIMUM TEMPERATURES IN THE MID TO UPPER 70S
RANGE. THERE IS A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS ON
SUNDAY AS SEVERAL SHORT-WAVE TROUGHS MOVE ACROSS THE AREA. FOR
EARLY NEXT WEEK...THE WEATHER PATTERN CHANGES AS A PACIFIC
NORTHWEST STORM MOVES ACROSS CALIFORNIA AND THEN INTO BAJA
CALIFORNIA AND NORTHWEST MEXICO. THE STORM SYSTEM IS FORECAST TO
DIG TO THE SOUTHEAST OF MEXICO AND INTO DEEP SOUTH TEXAS. A COLD
FRONT IS FORECAST TO PUSH FROM THE NORTHWEST TO SOUTHEAST WITH
PWATS INCREASING NEAR TWO STANDARDS DEVIATION. WITH THAT IN
MIND...POCKETS OF HEAVY RAIN ARE POSSIBLE...ESPECIALLY ACROSS THE
NORTHERN HILL COUNTRY AND EASTERN COUNTIES TUESDAY NIGHT INTO
WEDNESDAY. AT THIS TIME...THE ECM MODEL SOLUTION MAKES MORE SENSE
THAN GFS. THE GFS BRINGS THE UPPER LOW AND LINGERS AROUND FOR A
LONGER PERIOD ACROSS THE AREA. FOR NOW...WILL MONITOR AND ADJUST
THE EXTENDED FORECAST ACCORDINGLY AS MEDIUM- RANGE MODELS BECOME IN
BETTER AGREEMENT.


Fort Worth discussion:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
214 PM CST WED MAR 2 2016

A BROAD AREA OF SURFACE LOW PRESSURE OVER NORTHWEST TEXAS ON
TUESDAY MAY SUPPORT INCREASING COVERAGE OF THUNDERSTORMS ACROSS
NORTH TEXAS AND MAY EXTEND ACROSS THE ENTIRE DALLAS/FT WORTH METRO
AREA. HOWEVER THIS WILL BE HIGHLY DEPENDENT ON WHERE THE SURFACE
FEATURES SET UP AND HOW QUICKLY THE LOW BEGINS TO MOVE EASTWARD.
RIGHT NOW...HAVE SETTLED ON THE GFS SOLUTION AS IT HAS REMAINED
CONSISTENT. THE ECMWF SHOWS SIGNS OF BEING TO FAST IN ITS
PROGRESSION EASTWARD...WHICH IS USUALLY A PROBLEM WITH CLOSED
UPPER LEVEL LOWS MOVING OUT OF THE SOUTHWEST US/NORTHERN MEXICO.

[Texas Snowman]

Those that live by the model shall die by the model. So one of them is in trouble - the question is which one?!?

[JDawg512]

Well given that the Euro has been the more accurate of the group including predicting the last front being dry and has been spot on with this incoming front tomorrow morning being dry, it's logical to side with the Euro for next week as well. All that matters to me is that we get rain in Austin. Doesn't have to be a deluge but a good spread of 1.5 to 2.5 inches would be great.

[jasons2k]

Hoping for some decent rain next week. It looks more promising.

[Brent]

this run of the GFS is even wetter... has more widespread rain next Thursday from a low from the Gulf of Mexico that moves NW towards Austin... some amounts near 6" between DFW and Austin

ETA: The Euro agrees with the GFS on the 2nd surge of rainfall Thursday/Friday. Both models have over 3" of rain at DFW officially.

[KatDaddy]

Highs in the low 80s will drop into the mid 70s through the weekend behind a dry cool front this afternoon as nice Spring weather continues with mostly sunny to partly sunny skies. Still several days out but the threat for heavy rain and severe weather across a large portion of TX early next week remain. The SPC has 15% risk areas across portion of the S Plains for Monday and Tuesday. All of SE TX is included in the risk area Tuesday.

From this morning's Hou-Gal HWO:

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY
A STRONG UPPER LEVEL STORM SYSTEM WILL APPROACH TEXAS BY THE END
OF THE WEEKEND...PRODUCING A CHANCE OF THUNDERSTORMS FROM MONDAY
THROUGH WEDNESDAY. WHILE THERE ARE MAJOR UNCERTAINTIES REGARDING
THE DETAILS OF THIS SYSTEM...SOME POTENTIAL FOR STRONG OR SEVERE
STORMS AND HEAVY RAINFALL COULD EXIST ACROSS SOUTHEAST TEXAS
DURING THIS TIME.

[wxman57]

Here is some info on the ECMWF upgrade scheduled for March 8th:

https://software.ecmwf.int/wiki/display/FCST/Detailed+information+of+implementation+of+IFS+cycle+41r2

[Tireman4]

Here is some info on the ECMWF upgrade scheduled for March 8th:

https://software.ecmwf.int/wiki/display/FCST/Detailed+information+of+implementation+of+IFS+cycle+41r2

I am assuming this is a good thing?

[wxman57]

Here is some info on the ECMWF upgrade scheduled for March 8th:

https://software.ecmwf.int/wiki/display/FCST/Detailed+information+of+implementation+of+IFS+cycle+41r2

I am assuming this is a good thing?

Yeah, "upgrade" doesn't always mean "better", as we have seen with previous "upgrades" of the ETA/NAM/WRF. However, Ryan Maue has been verifying this upgrade (parallel run on his site) and it's verifying much better (500mb heights) than the current EC version and a lot better than the GFS. It should perform better with TCs as well.

From the upgrade notes (I think):

Tropical cyclones
The structural representation of tropical cyclones is improved with a
more clearly defined eye and better resolved rainbands. Evidence from
case studies shows that the increase in resolution leads to improved
forecasts of tropical cyclone intensity in the ENS. Initial ensemble spread
is also improved for tropical cyclones by the increased resolution in
the EDA. For HRES, the tropical cyclone impact of the resolution change
is smaller. Case studies show a better representation of the precipitation
pattern around the core of tropical cyclones in the new cycle. This
improvement is due to changes in model numerics (move to cubic grid
and changes in the semi-Lagrangian scheme).

[Ntxw]

Euro upgrades are usually meaningful, the resolution is already light years ahead of it's american counterpart. What the GFS has now essentially the euro was doing 5 years ago

[weatherdude1108]

I am assuming EWX is siding with the GFS. Anyway. Hope we get some decent wetting rains out of this in any case. Need the Bluebonnets to perk up.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
334 PM CST THU MAR 3 2016

.LONG TERM (SUNDAY THROUGH FRIDAY)...
THE WEATHER PATTERN ACROSS THE AREA IS FORECAST TO CHANGE AND
BRINGS RAIN CHANCES FOR MUCH OF NEXT WEEK. AN UPPER ZONAL PATTERN
IS EXPECTED FOR SUNDAY WITH SEVERAL SHORT-WAVE DISTURBANCES
MOVING ACROSS THE AREA AND CREATING ENOUGH LIFT FOR LIGHT SHOWERS
ACTIVITY ACROSS THE SOUTHERN EDWARDS PLATEAU AND RIO GRANDE
SUNDAY AFTERNOON. AS THE DAY PROGRESSES...A LARGER SHORT-WAVE
MOVING ACROSS THE FOUR CORNERS REGION IS FORECAST TO PUSH ACROSS
THE SOUTHERN PLAINS AND PRODUCE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS THE AREA...ESPECIALLY OVER THE HILL COUNTRY
AND EASTERN COUNTIES. THERE MAY BE A BREAK MONDAY EVENING BEFORE A
SECOND AND STRONGER ROUND OF SCATTERED TO NUMEROUS SHOWERS AND
ISOLATED THUNDERSTORMS AFFECT THE AREA LATE MONDAY NIGHT INTO MID
DAY TUESDAY. SOME OF THESE STORMS COULD BE STRONG TO SEVERE AS
THEY MOVE FROM A SOUTHWEST TO NORTHEAST DIRECTION. MAIN TREAT FOR
THIS PARTICULAR PERIOD WILL BE THUNDERSTORM DAMAGING WIND GUSTS
AND LARGE HAIL. ALSO...THERE IS THE POTENTIAL FOR POCKETS OF
ISOLATED HEAVY SHOWERS MAINLY ACROSS THE NORTHERN HILL COUNTRY AND
EASTERN COUNTIES. THE WETTER PATTERN CONTINUES THROUGH FRIDAY OF
NEXT WEEK AS AN UPPER STORM SYSTEM PUSHES ACROSS NORTHERN MEXICO
AND INTO OUR AREA BEFORE IT PUSHES TO THE NORTHEAST.

[Texas Snowman]

FXUS64 KFWD 032036
AFDFWD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FORT WORTH TX
236 PM CST THU MAR 3 2016

.LONG TERM...MAIN IMPACTS THIS FORECAST CYCLE WILL BE THE
DECREASING WIND SPEEDS THIS EVENING AND DRY CONDITIONS PERSISTING
INTO SUNDAY. BIGGER IMPACTS EXPECTED WITH THE TRANSITION OF THE
UPPER LEVEL PATTERN OVER THE WEEKEND/EARLY NEXT WEEK LEADING TO
SIGNIFICANT PROBABILITY FOR RAINFALL (DAY OVER DAY) NEXT WEEK AND
EVEN SOME POTENTIAL FOR SEVERE TSTMS MONDAY/TUESDAY. AT ANY
RATE...WHEN THE PATTERN BECOMES UNSETTLED BOTH LONG RANGE MODELS
ARE SHOWING SIGNALS FOR A RATHER WET WEEK.

CURRENTLY NORTH TEXAS IS IN THE WAKE OF A DRY COLD FRONT AND THE
PRESSURE GRADIENT THAT HAS BEEN DRIVING THE WINDS IS SLOWLY
RELAXING. THIS TREND IS EXPECTED TO CONTINUE THROUGH FRIDAY WITH
WINDS BECOMING LIGHT AND EVENTUALLY SWINGING FROM NORTH/NORTHWEST
TO SOUTHEAST OVER TIME. NO PRECIPIPATION IS FORECAST FOR THE
REGION THROUGH MOST OF THE WEEKEND. THERE IS A SMALL CHANCE NORTH
TX COULD SEE A SHOWER OR TWO BY EARLY SUNDAY AS THE LOW LEVEL
RETURN FLOW CONTINUES TO INCREASE MOISTURE VALUES ACROSS THE
REGION...BUT MOST AREAS WILL BE DRY UNTIL MONDAY.

BOTH THE GFS AND ECMWF ARE NOW SHOWING A SIMILAR TREND OF A STRONG
AND DEEP UPPER LEVEL TROUGH DIVING DOWN THE WEST COAST AND INTO
NORTHERN MEXICO. A QUICK MOVING SHORTWAVE DROPPING INTO THE
SOUTHERN PLAINS FROM COLORADO (MON/TUE) WILL LIKELY GENERATE
SHOWERS/TSTMS ACROSS NORTH TX. CURRENT LONG RANGE SPC OUTLOOKS
SHOW SOME POTENTIAL FOR SEVERE STORMS (HAIL/WIND DAMAGE) SOUTH AND
NORTH OF THE CWA...SO WILL CONTINUE TO MONITOR THE CHANGES
CLOSELY.

AS THE UPPER LEVEL TROUGH MOVES EASTWARD OVER MEXICO IT IS SHOWING
SIGNS OF BECOMING A VERY SLOW MOVING/CLOSED LOW OVER THE REGION.
BOTH MODELS ON THIS MORNINGS RUN SHOWED THIS SOLUTION AND IT IS
TYPICAL TO SEE THE MODELS STRUGGLE WITH MOVING THESE TYPE OF
CLOSED SYSTEMS TOO FAST TO THE EAST. HAVE KEPT WITH THE IDEA THAT
TUESDAY WILL BE THE BEGINNING OF THE HIGHEST POTENTIAL FOR HEAVY
RAINFALL. AS IS USUSAL WITH THIS TYPE OF PATTERN...SEVERAL WAVES
OF ENERGY...IN THE FORM OF UPPER LEVEL SHORT WAVES/JET STREAKS
WILL EJECT FROM THE UPPER LOW AND MOVE ACROSS CENTRAL AND NORTH
TEXAS. THESE WAVES WILL BE THE IMPULSES THAT WILL LIKELY INDUCE
WAVES OF MODERATE/HEAVY RAINFALL AS THEY TRAVERSE THE AREA FROM
EARLY TUESDAY THROUGH THURSDAY OR POSSIBLY FRIDAY.

TO SUMMARIZE...THINK THAT THE BIGGEST IMPACTS NEXT WEEK ARE GOING
TO BE FROM PROLONGED MODERATE OR GREATER RAINFALL EPISODES...WITH
AN EMBEDDED CHANCE OF STRONG TO POSSIBLY SEVERE WEATHER LATE
MONDAY/TUESDAY.

99
&&

[JDawg512]

I think the Euro and GFS are lining up in better agreement per what the early morning discussion suggested. I have better confidence when they start to forecast the same thing aside from the typical timing differences.

All in all I'm finally starting to get alittle excited for the upcoming week.

[gboudx]

Update from Jeff Lindner for next weeks weather:

Prolonged period of stormy weather heading for TX next week.

Major upper air pattern change will revert the recent strong of weeks of mostly dry weather into a much more stormy pattern by early next week. Potential for high impact episodes of severe weather and heavy rainfall will be possible from Tuesday to possibly Thursday and Friday of next week.

An upper level storm system currently south of the Gulf of Alaska will drop toward California and then SE into the SW US and N MX by early next week. The upper flow over TX will become SW on the east side of the large upper level trough dragging Pacific high level moisture and upper air disturbances into the region along with good low level moisture advection from the Gulf of Mexico. The upper level storm system slows and possibly even cuts-off (stalls) over NE MX or far W TX Tuesday into Wednesday pumping copious moisture into the region with favorable upper level winds spreading apart aloft to produce good lift of the moist air mass. End result appears to be several rounds of thunderstorms with both severe weather and heavy rainfall possible.

Timing of the individual upper air impulses around the main upper level trough is impossible to determine, but will likely be tied to the most active periods of next week. Models are keying in on Tuesday and Wednesday and again late Thursday into Saturday for potential for thunderstorm complex formation over SW TX which would move ENE into SE TX. Latest 12Z guidance did come in significantly wetter for the entire period, but models have not been showing good QPF forecasts these last few days on overall rainfall amounts and if a more significant flood threat is in the making.

Given we are still 3-4 days before any onset or impacts from the this system, the fine details will be worked out over the weekend into early next week along with the possible severe weather modes and rainfall totals.