October 2014: Slight Rain Chances/Halloween Outlook

[SLM87TX]

I seen they are mentioning that the line might be moving a little faster and be farther south. Wonder if we will see any of the severe weather tonight?

[srainhoutx]

I seen they are mentioning that the line might be moving a little faster and be farther south. Wonder if we will see any of the severe weather tonight?

The latest HRRR (High Resolution Rapid Refresh) guidance suggests the front will be NW of SE Texas in the early morning hours of Saturday.

[SLM87TX]

looks like Healthy looking line if it happens. Will there be any cap in place tomorrow morning to deteriorate it as it moves south like it did recently?

[srainhoutx]

looks like Healthy looking line if it happens. Will there be any cap in place tomorrow morning to deteriorate it as it moves south like it did recently?

The cap should erode as the line passes the Austin area in the morning around 12Z. Tomorrow could be rather wet and perhaps a bit chilly N of the front wherever it eventually stalls out. Below is the current surface analysis.

[srainhoutx]

Afternoon Briefing from Jeff:

Multiple storm systems to affect the state over the next 72 hours.

This afternoon-Saturday evening:
Cold front over NW TX is on the move early this afternoon even in the face of low level mixing which normally helps to slow up such boundaries. Temperature at Dallas is 90 while Perryton, TX in the panhandle is 52. Air mass ahead of this boundary is becoming very unstable with strong warm air advection regime in place across central and east TX pumping copious moisture northward. Air temperatures in the upper 80’s and dewpoints in the mid 60’s to mid 70’s are supporting CAPE values of 2500-3500 J/Kg ahead of the boundary. Capping noted around 700mb is eroding with strong frontal forcing and incoming lift from an upper level trough over the SW US. Numerous thunderstorms will erupt along the frontal boundary from NE MX to NE TX by late afternoon and move southeastward overnight. Severe threat for wind damage and large hail will be possible this evening mainly NW of SE TX. High resolution models bring this line of weather into SE TX between 1000pm and 300am tonight while showing a gradual weakening of the line. Actual front may stall inland of the coast early Saturday, but strong outflow boundary is support by meso models to push offshore and into deep south TX with scattered to numerous showers and thunderstorms along this feature. Not real sure where the front will come up stationary on Saturday, but meso models show little development on the boundary with the deep moisture being shunted south by the early morning outflow boundary.

Sunday-Monday:
Impressive upper level storm system heading for the US west coast drops SSE into the high plains this weekend and into the central plains early next week. Large scale ascent will overspread much of the southern plains late Sunday with the rapid formation of a surface cyclone over NW TX. This system quickly deepens to sub 1000mb Sunday night resulting in a developing strong pressure gradient over the state. Low level jet really cranks up Sunday evening to 50kts or better off the western Gulf which will quickly transport a moist and unstable air mass northward from the south TX coast to near the OK border by early Monday morning. Deepening surface cyclone (sub 1000mb) over OK will result in a strong cold front plowing southward across TX Monday.

While Sunday looks to be a fairly inactive…much of this depends on exactly where the cold front stalls out on Saturday as this feature will return northward Sunday ahead of the developing surface low over NW TX. Based on the frontal movement this afternoon and expected numerous storms along the boundary overnight, the boundary or its outflow, could easily push to the coast Saturday and then the question becomes how quickly does it lift northward on Sunday and do any storms attempt to develop on the northward moving warm front. The reason why this is important is that warm fronts can at times produce severe weather especially with such a dynamic looking system approaching from the west.

Bigger story will likely be on Monday as the strong cold front plows into a warm and unstable air mass over SE TX with high amounts of wind energy. Impressively dynamic storm system will bear impacts across the entire state. Linear forcing on the strong cold front supports a squall line developing over NW TX late Sunday night and progressing southeast Monday. Timing shows the front reaching SE TX around midday with some heating ahead of the line. Main question is does the air mass over SE TX becomes unstable enough to produce isolated supercells ahead of the main line. Very strong wind shear will be in place with 50kt low level jet at 2000 ft veering to 80kts at 5000 ft leading to both speed and directional wind shear. Any cells that can root near the surface will have a tornado threat if surface based instability is favorable enough. Squall line will move across the region Monday with a damaging wind threat along its leading edge. Capping may attempt to move into the area from the SW, but think a severe threat for wind damage is certainly warranted even this far out for Monday especially north of I-10 given the strong wind energy aloft. Cells will be moving quickly on the order of 35-45mph so while heavy rainfall looks likely, the flooding threat should be low given the fast storm motion as long as cell training does not develop.

Strong cold front will blast off the coast with cold air advection and gusty NW winds in the post frontal regime. Temperatures will fall from the 80’s into the 60’s with the frontal passage with NW winds of 25-35mph. Cold air striking the warm Gulf waters will result in gusts to gale force or better Monday night and strong coastal winds will continue for much of Monday night .

Tuesday through the end of next week will feature near perfect weather with mostly clear skies under surface high pressure with lows in the 50’s and highs in the 70’s to lower 80’s with low humidity.

Will update again on Sunday with a focus on the Monday storm system and severe threat.

[srainhoutx]

MESOSCALE DISCUSSION 1841
NWS STORM PREDICTION CENTER NORMAN OK
0226 PM CDT FRI OCT 10 2014

AREAS AFFECTED...SERN OK...N TX...FAR SWRN AR

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 101926Z - 102100Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...ISOLATED SEVERE HAIL AND LOCALLY STRONG WINDS SHOULD
DEVELOP AMIDST INCREASING STORM COVERAGE ALONG AND IMMEDIATELY
BEHIND THE SURFACE FRONT PUSHING S/SE ACROSS THE RED RIVER VALLEY.

DISCUSSION...19Z SURFACE ANALYSIS PLACED A 1010 MB CYCLONE AROUND 30
SW MLC ALONG A WAVY FRONTAL BOUNDARY THAT EXTENDED SW TO A 1009 MB
CYCLONE OVER THE CONCHO VALLEY OF W TX. INCREASING TSTM COVERAGE HAS
BEEN NEAR THE LEAD CYCLONE WITH AGITATED CU/INITIAL CBS FORMING OVER
A STRATUS DECK ACROSS THE TX BIG COUNTRY. AIR MASS WITHIN THE WARM
SECTOR IS LIKELY MODERATELY UNSTABLE WITH MLCAPE OF 1000-1500 J/KG
AMIDST SURFACE TEMPERATURES THROUGH THE 80S.

THE ANAFRONTAL/UNDERCUTTING NATURE OF THE FRONT SW OF THE LEAD
CYCLONE WILL BE A LIMITING FACTOR TO SUSTAINING SUPERCELL
DEVELOPMENT ALONG IT. BUT STEEP MID-LEVEL LAPSE RATES AND SUFFICIENT
DEEP SHEAR WILL FAVOR A RISK FOR ISOLATED LARGE HAIL AND STRONG WIND
GUSTS. FARTHER NE...VEERING LOW-LEVEL HODOGRAPHS AND STRONGER
MID/HIGH-LEVEL FLOW /AS SAMPLED BY SRX VWP DATA/ MAY COMPENSATE FOR
THE WEAKER LAPSE RATE ENVIRONMENT AND PREDOMINATELY CLUSTER MODE.
THIS COULD YIELD LOCALIZED SEVERE WIND AND PERHAPS A BRIEF WEAK
TORNADO.

..GRAMS/DARROW.. 10/10/2014


ATTN...WFO...LZK...SHV...TSA...FWD...OUN...SJT...

[srainhoutx]

Severe Thunderstorm Watch issued for portions of Oklahoma, Arkansas and N Texas...

Code: Select all

BULLETIN - IMMEDIATE BROADCAST REQUESTED
     SEVERE THUNDERSTORM WATCH OUTLINE UPDATE FOR WS 525
     NWS STORM PREDICTION CENTER NORMAN OK
     325 PM CDT FRI OCT 10 2014
     
     SEVERE THUNDERSTORM WATCH 525 IS IN EFFECT UNTIL 1000 PM CDT
     FOR THE FOLLOWING LOCATIONS
     
     ARC061-081-097-109-113-127-133-149-110300-
     /O.NEW.KWNS.SV.A.0525.141010T2025Z-141011T0300Z/
     
     AR 
     .    ARKANSAS COUNTIES INCLUDED ARE
     
     HOWARD               LITTLE RIVER        MONTGOMERY          
     PIKE                 POLK                SCOTT               
     SEVIER               YELL                
     
     
     OKC005-013-019-023-029-067-069-077-079-085-089-095-099-121-127-
     110300-
     /O.NEW.KWNS.SV.A.0525.141010T2025Z-141011T0300Z/
     
     OK 
     .    OKLAHOMA COUNTIES INCLUDED ARE
     
     ATOKA                BRYAN               CARTER              
     CHOCTAW              COAL                JEFFERSON           
     JOHNSTON             LATIMER             LE FLORE            
     LOVE                 MARSHALL            MCCURTAIN           
     MURRAY               PITTSBURG           PUSHMATAHA          
     
     
     TXC009-077-085-097-113-119-121-133-147-181-223-231-237-277-337-
     363-367-387-397-429-439-485-497-503-110300-
     /O.NEW.KWNS.SV.A.0525.141010T2025Z-141011T0300Z/
     
     TX 
     .    TEXAS COUNTIES INCLUDED ARE
     
     ARCHER               CLAY                COLLIN              
     COOKE                DALLAS              DELTA               
     DENTON               EASTLAND            FANNIN              
     GRAYSON              HOPKINS             HUNT                
     JACK                 LAMAR               MONTAGUE            
     PALO PINTO           PARKER              RED RIVER           
     ROCKWALL             STEPHENS            TARRANT             
     WICHITA              WISE                YOUNG               
     
     
     ATTN...WFO...SHV...FWD...OUN...TSA...LZK...
     

[Paul Robison]

Afternoon Briefing from Jeff:

Multiple storm systems to affect the state over the next 72 hours.

This afternoon-Saturday evening:
Cold front over NW TX is on the move early this afternoon even in the face of low level mixing which normally helps to slow up such boundaries. Temperature at Dallas is 90 while Perryton, TX in the panhandle is 52. Air mass ahead of this boundary is becoming very unstable with strong warm air advection regime in place across central and east TX pumping copious moisture northward. Air temperatures in the upper 80’s and dewpoints in the mid 60’s to mid 70’s are supporting CAPE values of 2500-3500 J/Kg ahead of the boundary. Capping noted around 700mb is eroding with strong frontal forcing and incoming lift from an upper level trough over the SW US. Numerous thunderstorms will erupt along the frontal boundary from NE MX to NE TX by late afternoon and move southeastward overnight. Severe threat for wind damage and large hail will be possible this evening mainly NW of SE TX. High resolution models bring this line of weather into SE TX between 1000pm and 300am tonight while showing a gradual weakening of the line. Actual front may stall inland of the coast early Saturday, but strong outflow boundary is support by meso models to push offshore and into deep south TX with scattered to numerous showers and thunderstorms along this feature. Not real sure where the front will come up stationary on Saturday, but meso models show little development on the boundary with the deep moisture being shunted south by the early morning outflow boundary.

Sunday-Monday:
Impressive upper level storm system heading for the US west coast drops SSE into the high plains this weekend and into the central plains early next week. Large scale ascent will overspread much of the southern plains late Sunday with the rapid formation of a surface cyclone over NW TX. This system quickly deepens to sub 1000mb Sunday night resulting in a developing strong pressure gradient over the state. Low level jet really cranks up Sunday evening to 50kts or better off the western Gulf which will quickly transport a moist and unstable air mass northward from the south TX coast to near the OK border by early Monday morning. Deepening surface cyclone (sub 1000mb) over OK will result in a strong cold front plowing southward across TX Monday.

While Sunday looks to be a fairly inactive…much of this depends on exactly where the cold front stalls out on Saturday as this feature will return northward Sunday ahead of the developing surface low over NW TX. Based on the frontal movement this afternoon and expected numerous storms along the boundary overnight, the boundary or its outflow, could easily push to the coast Saturday and then the question becomes how quickly does it lift northward on Sunday and do any storms attempt to develop on the northward moving warm front. The reason why this is important is that warm fronts can at times produce severe weather especially with such a dynamic looking system approaching from the west.

Bigger story will likely be on Monday as the strong cold front plows into a warm and unstable air mass over SE TX with high amounts of wind energy. Impressively dynamic storm system will bear impacts across the entire state. Linear forcing on the strong cold front supports a squall line developing over NW TX late Sunday night and progressing southeast Monday. Timing shows the front reaching SE TX around midday with some heating ahead of the line. Main question is does the air mass over SE TX becomes unstable enough to produce isolated supercells ahead of the main line. Very strong wind shear will be in place with 50kt low level jet at 2000 ft veering to 80kts at 5000 ft leading to both speed and directional wind shear. Any cells that can root near the surface will have a tornado threat if surface based instability is favorable enough. Squall line will move across the region Monday with a damaging wind threat along its leading edge. Capping may attempt to move into the area from the SW, but think a severe threat for wind damage is certainly warranted even this far out for Monday especially north of I-10 given the strong wind energy aloft. Cells will be moving quickly on the order of 35-45mph so while heavy rainfall looks likely, the flooding threat should be low given the fast storm motion as long as cell training does not develop.

Strong cold front will blast off the coast with cold air advection and gusty NW winds in the post frontal regime. Temperatures will fall from the 80’s into the 60’s with the frontal passage with NW winds of 25-35mph. Cold air striking the warm Gulf waters will result in gusts to gale force or better Monday night and strong coastal winds will continue for much of Monday night .

Tuesday through the end of next week will feature near perfect weather with mostly clear skies under surface high pressure with lows in the 50’s and highs in the 70’s to lower 80’s with low humidity.

Will update again on Sunday with a focus on the Monday storm system and severe threat.

Don't you agree with SPC's severe threat projection?


They say the threat for severe storms/damaging winds lies to the north/northeast of the Houston Metro. Do you personally feel it more likely all of Houston (not just north of I-10) will be hardest hit by this squall line? Please clarify.

[srainhoutx]

The new Day 3 Severe Outlook from the Storm Prediction Center suggests the greatest threat for severe weather on Monday will be NE of Texas in the Mid Mississippi River Valley Region. That does not mean there is zero chance of severe storms across all of SE Texas. This is likely to be a quick moving mid to early afternoon squall line and the risk of damaging thunderstorm winds and an isolated quick spin up of a tornado or two along the line is not out of the question.

Meanwhile the front continues to advance toward the SE Texas area this morning and should stall somewhere near the I-10 Corridor later today. The WPC has issued a Slight Risk for Excessive Rainfall across portions of the I-35 Corridor near or just N of Austin and Waco on NE into the Texarkana area and Southern Arkansas.

[Karen]

I keep reading the front will stall does that mean we wont be getting the cooler weather this week?

[srainhoutx]

I keep reading the front will stall does that mean we wont be getting the cooler weather this week?

There is a much stronger Pacific front crossing Texas on Monday bringing the severe weather threat and Fall like tempertures most of next week Karen.

[Karen]

Thanks looking forward to fall again

[skidog40]

front made it here

[Kingwood32]

There was a front? ..I don't feel anything different

[srainhoutx]

The weak cold front that brought the rain yesterday is beginning to retreat N across the Coastal waters of the NW Gulf. Showers and storms may develop later today as the weak front passes and we return into a strong southerly flow off the Gulf across the area. Further N across N Texas and Oklahoma, severe storms look likely as a potent short wave and deep trough drops SE from Utah into New Mexico later today. As cyclogenesis begins in earnest this evening and today, a strong Pacific front will begin its march E across the Region. A very strong squall line with damaging winds and an isolated tornado or two are possible tomorrow along the leading edge of the squall line where any bowing structure develop. We will need to monitor for any super cells developing ahead of the squall line where the tornado threat may increase mainly N of I-10 and specifically NE of the Houston Metro area across the Piney Woods of E Texas into Louisiana/Arkansas and Eastern Tennessee. It is possible we could see the Storm Prediction Center issue a Moderate Risk for severe storms later today across portions of E Texas and the Mid Mississippi Valley. Fall like weather will follow this potent storm system with gusty NW winds and perhaps some wrap around clouds as the low pressure deepens Monday night into Tuesday. This is a very dynamic storm system, so stay tuned tomorrow morning into the daytime hours for any further updates.

[srainhoutx]

Morning Briefing from Jeff:

Severe weather threat Monday as a strong fall storm system moves across the plains.

Weak cold front that pushed across SE TX on Saturday has stalled along the coast and is starting to move back northward this morning. Front is noted by dewpoint temperature contrast from 74 at Galveston to low 60’s inland. Radar shows scattered showers and thunderstorms from College Station to Victoria in response to strong jet streak lift aloft working on returning moisture. High resolution models show additional shower and thunderstorm development today as the coastal boundary begins to quickly move northward.

Powerful upper level storm system over the western US is digging SSE toward the high plains this morning. Surface pressure over the TX panhandle area already tanking with Amarillo reporting 29.79in and falling rapidly. As upper level divergence continues to overspread the plains today ahead of the strong trough, surface low pressure will continue to deepen over the TX panhandle. Deepening surface pressures will result in the rapid formation of a low level jet this afternoon and evening which will quickly return Gulf moisture northward across much of east TX. Low level jet maxes out at near 60kts early Monday while a powerful jet stream cores into the underside of the upper level storm system…this jet was sampled by ROAB network at nearly 170kts over Washington state this morning.

A surface cold front will attached to the deepening surface cyclone over OK Monday morning and quickly plow SE across TX. Very favorable dynamics and strong lift along the front will support the rapid formation of a squall line. Warm sector air mass appears capped so linear forcing on the front will be the main driver for strong to severe convection which will help cut down the tornado threat (low chance of warm sector supercells). Front should reach SE TX around College Station between 600-1000am and rapidly move off the coast by late afternoon…this timing might be a little slow. Modest warming of the air mass in the warm sector will promote squall line with bowing segments especially north of I-10 where strongest dynamics and weakest capping will be a play. Cap builds to the SW over Matagorda Bay where SSW to SW mid level flow will bring warm layer off NE MX mountains. Very favorable wind energy aloft will be transported toward the surface in thunderstorms to support a wind damage threat with the squall line. Bow segments are likely where mid level flow is transported to the surface supporting leading edge wind gusts of 60-70mph. Best threat appears to be over deep east TX into LA where categorical upgrade to moderate risk by SPC is possible given the threat for widespread wind damage. A few short lived tornadoes will also be possible at the couplet bows in the squall line as this is a common location for weak tornado formation. Should the warm sector destabilize faster than expected Monday morning a few supercells with tornadoes could develop ahead of the main line, but this threat appears low at this time. SPC currently has all SE TX outlooked in a slight risk for Monday, but think the SW portion of this risk area is very marginal with capping around Matagorda Bay.

Severe threat rapidly ends with the frontal passage. Strong NW winds will develop in the post frontal regime across all of SE TX Monday afternoon. Rapid clearing may help to offset the cooling behind the front, but will help in mixing of strong winds to the surface. Very strong offshore flow develops Monday night with gusts to 40mph or better over the nearshore waters as the departing storm system continues to deepen to our NNE.

Cool mornings with lows in the low 50’s and highs in the mid 70’s under sunny skies is expected Tuesday-Thursday as surface high pressure builds southward behind the departing storm system.


SPC Day 2 (Monday) Severe Weather Outlook:

[jasons2k]

Here it comes, and the outflow just pushed out ahead of it too. Any wagers it skips over me?

[mckinne63]

Here it comes, and the outflow just pushed out ahead of it too. Any wagers it skips over me?

Shall we roll the dice?

Heavy rains here in Stafford. It cleared and now it's clouding up again and hearing thunder.

[jasons2k]

It poured pretty hard, but it was quick. At least I'm getting enough rain to water the lawn.

[Paul Robison]

Hi, everybody.

The severe threat is STILL north of 1-10 and ne of the Houston metro, right? So how do things look for areas like SW Houston and the downtown area? Am I likely to lose power in the Memorial area where I am?

(p.s: am I imagining things or are you guys forecasting a DERCHO for Monday's weather? Pardon my drama, but to put it bluntly, this things sounds like a real----blast!)

Would like an answer ASAP