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Near record heat will be building across the state today and Friday.
Weak boundary pushing across the region this morning…hard to call it a cool front…more like a dry line with dewpoints falling into the lower 60’s north of the boundary. Just above the surface 30-40kts of westerly wind is found and this will mix down once a few hours of heating are completed. Westerly winds in SE TX are dry/hot winds this time of year and today will be no exception. Expect many locations to reach their first 90 today which falls short of any records.
Heat really cranks in on Friday as ridging builds out of Mexico. Low to mid 100’s will build NE out of the Rio Grande plains into S TX with widespread mid to upper 90’s across all of S and C TX and low to mid 90’s across SE TX. Record at IAH is 94 in 1998 and this looks to be in jeopardy. 850mb temps. rise into the low to mid 20C range across the area with the highest values around Matagorda Bay closest to the building ridge aloft. Low level southerly winds will keep very humid surface conditions in place and when combined with the high temps…will produce heat index values well over 100. Will repeat again on Saturday only a few degrees cooler.
Weak front approaches on Sunday and this should help bring temps. back toward normal. With ridging aloft and strong cap in place feel chances for rain are slight even with good moisture in place. Will need to keep an eye out to the W both Friday, Saturday, and Sunday afternoons as the dry line may be able to fire off an isolated severe storms that could make a run for our N or W counties. Given the forecasted high temps in the mid to upper 90’s along the dry line there will be all kinds of surface instability in place…but the capping will have to be breached to release it vertically.
Horrible model agreement after Monday as GFS is at odds with ECMWF on placement of large closed upper low and associated weather. GFS has the low parked over the Great Lakes…and a drier forecast while the ECMWF has it over New Mexico with SW flow aloft over TX and a wetter forecast. Climatology would tend to favor the ECMWF….we shall see! With such poor model agreement will go with a status quo forecast through next Wednesday with the understanding that significant adjustments may be needed as the models start to converge toward a solution.
hiflyer wrote:Birmingham about to get sucker punched with Atlanta next (CNN already freakin). Suspect evening news will be tornado 101 from Tupelo east to Atlanta. these midwest storms have been tough over the past week....went to/from the west coast from Ft Lauderdale via Denver and both ways went all the way north of St Louis to get around...and still bounced all over the sky especially yesterday coming back. All altitudes and all routes...that is a lot of unstable air.
C TX dry line setting up along the I-35 corridor this afternoon with weak southerly winds returning to SE TX adding surface moisture. Strong surface heating is making for a very unstable afternoon atmosphere…but capped off by a strong inversion. Short term models continue to insist that the cap will be breached and severe thunderstorms will rapidly develop after 300pm along I-35 and push ESE into our W and N counties this evening.
Concern is warranted given potential CAPE of 4000-5000 J/kg and strong deep layer shear given forecasted afternoon temps in the low to upper 90’s over C and SE TX. IF the cap is broken explosive supercell development will occur and SPC has upgraded the N and W parts of our area into a slight risk. Things will happen very quickly…ie from clear skies to severe/tornadic storms in 20-40 minutes if the cap is broken and surface instability released. Pattern and instability parameters are somewhat similar to the May 1997 tornado outbreak over C TX which produced the killer F5 Jarrell, TX tornado. Feel the storms that do develop…if any will be isolated…but could potentially be very dangerous. Will see how things unfold late this afternoon.
Weak cold front should move into a highly unstable/capped air mass late Saturday afternoon/evening. Once again if the cap is breached strong to severe thunderstorms appear likely given tremendous instability and modest shear. Best threat this go will be found N of I-10 and E of I-45 and may be more between midnight Saturday and 600am Sunday.
Sunday: Mostly cloudy, with a high near 83. North wind between 10 and 15 mph.
Sunday Night: Partly cloudy, with a low around 54. North wind around 5 mph.
Monday: Mostly sunny, with a high near 84. East wind between 5 and 10 mph.
THE LATTER HALF OF THE WEEK LOOKS INTERESTING. THE UPPER LOW IS
FORECAST TO EJECT EAST ACROSS TEXAS LATE WEDNESDAY/THURSDAY IN
ADVANCE OF AN UNSEASONABLY STRONG LONGWAVE TROUGH THAT IS FORECAST
TO DEVELOP OVER THE PLAINS STATES. THIS UPPER LOW IS FORECAST TO
TRACK FARTHER SOUTH THAN MOST OF THE SYSTEMS THIS SPRING SO
FAR. FLOW ALOFT BECOMES STRONGLY DIFFLUENT BY LATE WEDNESDAY AS SE
TX GOES INTO THE RIGHT REAR QUAD OF UPPER JET. PERSISTENT 30-40
KT LOW LEVEL JET WILL KEEP THE DEEP TROPICAL MOISTURE IN PLACE.
HAVE NUDGED POPS UPWARD WED/WED NIGHT...WITH SLOW MOVING SFC FRONT
SERVING AS A FOCUS FOR CONVECTIVE DEVELOPMENT. MODEL FORECAST
SOUNDINGS SUPPORT POTENTIAL OF SEVERE AND LOCALLY HEAVY RAINFALL
AS ALLUDED TO IN THE HWOHGX. COLD FRONT PUSHES OFF THE COAST THU
MORNING...WITH AT LEAST A SHORT PERIOD OF DRYING TAKING PLACE.
BOTH GFS/ECMWF SHOW THE LONGWAVE TROUGH AND AN ASSOCIATED
REINFORCING COLD FRONT CROSSING THE CWA FRIDAY. DIFFLUENT FLOW
ALOFT AND COOLING MID LEVELS IN ASSOCIATION WITH THE TROUGH
SUPPORT SOME CONVECTIVE POTENTIAL FRIDAY. HAVE ADDED 20 POPS TO
FORECAST WITH STILL PLENTY OF TIME TO WATCH. THIS PATTERN CHANGE
WILL SUPPORT A COOLING TREND BEGINNING THURSDAY.
Extremeweatherguy wrote:We'll see..
The SPC still has us under a SLIGHT RISK ( http://www.spc.noaa.gov/products/outlook/day1otlk.html ), but considering their track record so far this season, I am not going to be convinced until I see the storms actually forming.
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