Weather Forecast Discussion 10-26-09

FORECAST DISCUSSION:
10:05 AM Oct. 26, 2009


SHORT TERM: COLD AIR ADVECTION CONTINUES THIS MORNING AS COLD FRONT SURGES SE AWAY FROM THE REGION. WINDS HAVE REMAINED ELEVATED THIS MORNING CREATING WIND CHILLS IN THE 20'S AND 30'S ACROSS WEST TEXAS. RAIN SHOWERS AND EVEN A THUNDERSTORM CONTINUE THIS MORNING AS WELL. 7AM OBS SHOW SNOW AT RUIDOSO AND SANTA FE, SO SKI REPORTS SHOULD START TO LOOK GOOD IN THE NEXT 30 DAYS. FOR THE REST OF THE AFTERNOON. EXPECT COLD DOME TO REMAIN AND AS SUCH, CLOUD COVER WILL LIKELY RESIDE OVER MUCH OF THE REGION. HAVE OPTED TO STAY CLOSER TO THE COLDER WRF MOS GUIDNCE FOR AFTERNOON HIGH'S AND OVERNIGHT LOWS. THINK THAT THE CLOUD DECK WILL START TO BREAK LATE THIS AFTERNOON OR EARLY THIS EVENING. IN ANY CASE... EXPECT CLEAR SKIES TONIGHT. WINDS ARE ALSO EXPECTED TO WEAKEN ALLOWING FOR EXCELLENT RADIATIONAL COOLING ACROSS MUCH OF THE REGION. A FREEZE WARNING HAS BEEN HOISTED FOR THE MARFA PLATEAU AND DAVIS MTNS. THIS LOOKS TO BE A GOOD CALL. WRF MOS IS SUGGESTIVE OF UPPER TEENS/LWR 20'S AT KMRF TONIGHT. THUS A KILLING FREEZE IS EXPECTED AND HAVE ADVISED RESIDENTS IN THE ABOVE MENTIONED AREA TO BRING IN PLANTS AND PETS AND INSULATE PIPES. WHILE IT WILL BE COLD, IT DOESN'T APPEAR LIKELY THAT A KILLING FREEZE WILL IMPACT THE PERMIAN BASIN. HOWEVER, IT SHOULD BE NOTED THAT WRF MOS SHOWS LOWS IN THE MID 30'S AT KGNC AND KINK. THESE AREAS SHOULD BE MONITORED CLOSELY BY EVENING SHIFT AS MODELS OFTEN MISS THE FULL IMPACT OF SUCH RADIATIONAL EVENTS. WOULDN'T BE SHOCKED TO SEE LOWS DIP TO 32-33 ACROSS LEA AND GAINES COUNTIES.

LONG TERM: WARMER TEMPS ON TAP TUE AND WED AS SFC HIGH MOVES INTO SOUTH TEXAS AND SFC LOW OVER THE CNTL PLAINS STRENGTHENS. THIS SHOULD FORCE SFC TO 700MB WINDS TO VEER WRLY AND DOWNSLOPE COMPRESSIONAL WARMING WILL GET UNDERWAY. THIS COMBINED WITH SUNNY TO PARTLY CLOUDY SKIES WILL ALLOW TEMPS TO WARM INTO THE 70'S AND 80'S BOTH DAYS. THINK THAT THE GRADIENT WILL TIGHTEN AT THE SFC AND STRONGER H7 FLOW WILL MIX TO THE SFC BOTH DAYS. HAVE INTRODUCED BREEZY WORDING ON TUE AND WINDY WORDING ON WED TO ACCOUNT FOR THIS.

BY WEDNESDAY... VIGAROUS UPPER LOW WILL BE DIGGING SOUTH THROUGH THE FOUR CORNERS. USED THE WRF MODEL FOR THIS AS IT SEEMS TO BE DOING A GREAT JOB WITH THE EVOLUTION OF THIS FEATURE. WRF H3 PROGS SHOW A STOUT 170-180KT 300MB JET DIGGING DOWN THE BACK SIDE OF THIS FEATURE INDICATING IT WILL BE SLOWER AND FURTHER SOUTH THAN PREVIOUSLY THOUGHT. THE GFS IS ALSO MUCH SLOWER THAN YESTERDAY'S RUN SUPPORTING THIS THINKING. SFC PROGS SHOW PACIFIC COLD FRONT NEAR THE TX/NM STATE LINE BY 12ZTHUR. THINK THAT RAPID MOISTURE RETURN WILL OCCUR AHEAD OF THIS FRONT AND WITH STRONG DIVERGNCE ALOFT, WOULDN'T BE AT ALL SURPRISED TO SEE A SQUALL LINE DEVELOP OVER THE CNTL AND EASTERN PERMIAN BASIN EARLY THURSDAY MORNING. THE STRENGTH OF UPPER FLOW SUGGESTS RAPIDLY MOVING CELLS IN EXCESS OF 50KTS. THUS, DAMAGING WINDS APPEAR POSSIBLE. SPC HAS DRAWN IN A 5% HATCHED AREA OVER MUCH OF THE PERMIAN BASIN NORTH THROUGH THE PANHANDLE. THINK AN UPGRADE TO A SLIGHT RISK WILL BE SEEN IN THE NEXT DAY OR SO.

BEHIND THE FRONT... IT IS TOUGH TO SAY WHAT WILL HAPPEN TO TEMP PROFILES. THE PACIFC NATURE OF THE FRONT SUGGESTS THAT THE AIRMASS MIGHT NOT BE AS COLD AS PREVIOUSLY THOUGHT. HOWEVER, WRF AND ECMWF H85 PROGS SHOW A VERY COLD AIR MASS WITH TEMPS RANGING FROM -2 TO 3-4c RESPECTIVELY OVER OUR AREA. THE UKMET IS EVEN COLDER WITH THIS AIRMASS SHOWING SOME OF THE H85 AIR IN THE -6TO-7RANGE OVER THE WNW COUNTIES. TAKING ALL OF THIS INTO ACCOUNT, HAVE OPTED TO KEEP WITH A MUCH COLDER FORECAST THAN NWS OR EVEN THE MOS OFFERINGS SUGGEST. INFACT, THINK THAT THE HIGH ON THURS WILL OCCUR BEFORE SUNRISE WITH COOLING TEMPS THROUGH THE DAY. HOW MUCH COOLING IS DEPENDNT ON A NUMBER OF THINGS INCLUDING THE TIMING OF THE H5 VORT MAX, PRECIP, AND THE DEPTH OF THE COLD AIR. THE DEPTH OF THE H5 TROUGH IS CONCERNING AS ARTIC AIR COULD BE PULLED SOUTH AND EVEN THOUGH THE INITIAL WIND SHIFT IS PACIFIC IN NATURE, THE ARTIC AIR COULD BACKDOOR INTO THE AREA. WILL HOLD ON A DRASTIC DROP IN TEMPS FOR NOW AND WILL LEAVE A STEADY TO SLIGHT COOLING TREND IN PLACE THROUGH THE DAY ON THURSDAY. HOWEVER, SPECIAL ATTENTION SHOULD BE PAID TO THE SFC OBS AND SOUNDINGS FROM THE PACIFIC NW THROUGH THE NEXT 36HRS AS THIS WILL TELL THE STORY. CURRENT THINKING IS THAT MODELS WILL PROBABLY COOL TEMPS OVER THE NEXT FEW RUNS AS SOUNDING DATA FROM THE ABOVE MENTIONED AREA IS FED INTO THE MODELS. AS FAR AS PRECIP TYPE GOES... THINK THAT WE WILL SEE SNOW ABOVE 6500' HOWEVER, THE LOW LEVELS APPEAR TO BE TOO WARM FOR ANYTHING TO MIX OUT ONTO THE PLAINS UNLESS THE UKMET VARIFIES, THEN, SNOW MIGHT HAVE TO BE INTRODUCED OVER EDDY AND LEA COUNTY AS WELL AS PARTS OF THE NW PERMIAN BASIN. CONFIDNCE IN THE LATTER ISN'T HIGH ATTM.

KEPT A CHANCE OF TSRA IN THE FORECAST ON FRIDAY MORNING BANKING ON THE SLOWER EJECTION OF THE UPPER LOW. HOWEVER, EVEN AT A SLOWER PACE... A BULK OF THE DYNAMICS SHOULD BE WELL EAST OF THE AREA BY FRIDAY AFTERNOON WITH DECREASING CLOUDS AND WARMER TEMPS NOTED. THINK THAT ZONAL FLOW WILL PREVAIL SATURDAY AND SUNDAY WILL LITTLE IN THE WAY OF MOISTURE. WENT WITH SUNNY SKIES, WARMER AFTERNOONS AND COOL NIGHTS THROUGH THE WEEKEND. THE ECMWF AND TO A LESSER EXTENT THE GFS... SUGGEST A WEAK FRONT LATE IN THE WEEKEND/EARLY NEXT WEEK.



FIRE WEATHER: FIRE DANGER APPEARS TO BE ELEVATED OVER THE WESTERN 2/3 OF THE AREA ON TUE AND WED WITH DRY DOWNSLOPE WINDS. 20' WINDS ARE EXPECTED TO BE WELL ABOVE 20MPH AND Td ARE QUESTIONABLE. THUS, RED FLAG CONDITIONS ARE NOT OUT OF THE QUESTION. THINK MAF WILL DO A GOOD JOB WITH THIS, AND WILL FOLLOW THEIR LEAD.
TROPICS: N/A

CLOUD COVER
MON: M/C TUE: S WED: P/C THUR: M/C FRI: D/C SAT: S SUN: S

TEMPS
MON: XX/53 TUE: 49/73 WED: 52/79 THUR: 54/52 FRI: 37/65 SAT: 44/74 SUN: 49/77

MORGAN