Severe Thunderstorm Warning 12, NWS Amarillo, TX

TEXAS/OKLAHOMA PANHANDLES FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AMARILLO TX
431 PM CST FRI MAR 23 2001

MINOR WAVE MVG OVER SRN ROCKIES ALREADY WITH LOW LEVEL BOUNDARIES AND
MOISTURE CONVERGENCE HAS AIDED IN CONVECTIVE INITIATION ACROSS THE OK
PNHDL/NWRN AND SERN TX PNHDL AND ERN NM THIS AFTN. SFC LOW LOCATED IN
E CNTRL NM WITH INVERTED TROUGH EXTNDNG NE INTO SWRN KS HAS ALLOWED
BL WINDS TO BACK ACROSS MUCH OF THE TX/OK PNHDLS. THEREFORE...
OROGRAPHIC FORCING IS FURTHER ENHANCING LOW LEVEL LIFT.

12Z SHORT RANGE MODELS WERE IN MODERATE AGREEMENT OVER THE NEXT
COUPLE OF DAYS WITH MAIN DIFFERENCES IN THE STRENGTH OF COLD
AIRMASS CENTERED IN THE N CNTRL U.S. AVN IS BIT MORE AGRESSIVE WITH
FRONTAL PASSAGE TONIGHT THAN WAS 24 HRS AGO...AND SO IS NGM. LATEST
AVN/NGM MOS NUMBERS REFLECT THIS DOWNWARD TREND AS WELL. AS TYPICAL
WITH COLD SHALLOW AIR MOVING S ACROSS THE HIGH PLAINS...ETA WAS
ALREADY ONTO THIS LAST FEW RUNS. IN THE MEANTIME...SLIGHT RISK OF
SVR SEEMS PLAUSIBLE THROUGH THE EARLY EVEN IN CNTRL AND WRN ZONES.
YET WITH LOSS OF AFTN HEATING...MARGINAL INSTABILITY WILL GRADUALLY
DIMINISH AND SO WILL SVR THREAT. STRONG COLD FRONT WAS ORIENTED FROM
E CNTRL CO TO N CNTRL KS LATE THIS AFTN AND IS EXPECTED TO ENTER THE
OK PNHDL BY LATE EVENG...AND THE REST OF THE CWFA DURING THE
PREDAWN HOURS. 850MB TEMPS ARE EXPECTED TO DROP BELOW 0 DEG C BY
LATE IN THE DAY ON SAT WHICH WILL BRING ABT THE THREAT FOR A MIXTURE
OF RA AND SN...PARTICULARLY THE N CNTRL AND NE. HOWEVER...MOST OF
SYNOPTIC SCALE LIFT WILL HAVE SHIFT WELL EAST BY SAT NIGHT...THAT
ONLY A SLIGHT CHANCE FOR PRECIP LOOKS POSSIBLE.

FOR THE EXTENDED...NOT MUCH TIME TO INTERROGATE THE MEDIUM RANGE
MODELS IN DETAIL. YET DID NOTICE THAT THE MRF HAS FLIPPED AROUND
FROM PREVIOUS RUNS BY THE TIME THE MIDDLE OF NEXT WEEK ROLLS
AROUND. IN FACT...LATEST AVN IS MUCH WEAKER AND FARTHER N WITH NRN
STREAM WAVE EARLY NEXT WEEK COMPARED TO THE MRF. WITH THIS IN MIND...
DID NOT WANT TO INTRODUCE POPS FOR WED AND LOWER TEMPS FOR ALL OF
THE EXTNDD. HOWEVER...DID INTRODUCE SLIGHT CHANCE POPS FOR SUN NIGHT
DUE TO STRENGTHENING WAA REGIME AND INTRODUCED CHANCE POPS FOR MON
ASE WX PATTERN TRYING TO COME TOGETHER FOR A DRYLINE-INVOLVED
CONVECTIVE EVENT. OTHERWISE...NO OTHER CHANGES.

.AMA...
.TX...NONE.
.OK...NONE.

JH

OKZ001>003-TXZ001>020-240300-

TEXAS/OKLAHOMA PANHANDLES THUNDERSTORM OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE AMARILLO TX
212 PM CST FRI MAR 23 2001

THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS LATER THIS AFTERNOON
THROUGH TONIGHT OVER ABOUT THE WESTERN TWO-THIRDS OF THE OKLAHOMA AND
TEXAS PANHANDLES.  THE SLIGHT RISK AREA IS MAINLY ALONG AND WEST OF A
LINE FROM NORTHWEST OF FORGAN TO HEDLEY.  THIS DOES INCLUDE THE
CITIES AND TOWNS OF AMARILLO...BORGER...DALHART...CANYON...
HEREFORD...DUMAS...CLARENDON...SPEARMAN...GUYMON...STRATFORD...BOISE
CITY...CLAUDE...AND PERRYTON.

ELSEWHERE ACROSS THE EXTREME EASTERN OKLAHOMA AND TEXAS PANHANDLES...
SCATTERED THUNDERSTORMS ARE EXPECTED LATER TODAY THROUGH TONIGHT.
THUNDERSTORMS OVER THE HIGHER TERRAIN AND MOUNTAINS OF NORTHERN AND
NORTHEASTERN NEW MEXICO AS WELL AS SOUTHERN AND SOUTHEASTERN
COLORADO WILL MOVE SOUTHEAST INTO THE OKLAHOMA AND TEXAS PANHANDLES
BY MID TO LATE AFTERNOON TODAY.

A MOIST AND UNSTABLE AIRMASS IS IN PLACE OVER THE OKLAHOMA AND TEXAS
PANHANDLES.  IN ADDITION...A TROUGH OF LOW PRESSURE IN THE UPPER
ATMOSPHERE WILL MOVE EAST OUT OF NEW MEXICO AND INTO WEST TEXAS LATER
TODAY AND TONIGHT.  THAT IS THE REASON FOR THE SLIGHT RISK AREA OVER
THE WESTERN TWO-THIRDS OF THE OKLAHOMA AND TEXAS PANHANDLE THIS
EVENING AND TONIGHT.

THE PRIMARY THREATS WITH THE SEVERE THUNDERSTORMS WILL BE LARGE HAIL
AND DAMAGING DOWNBURST WINDS.

OUTSIDE OF THE SEVERE THREAT...THE THUNDERSTORMS ARE EXPECTED TO
PRODUCE BRIEF GUSTY WINDS...DEADLY LIGHTNING AND BRIEF HEAVY
RAINFALL.

SPOTTER GROUPS AND EMERGENCY MANAGEMENT OFFICIAL ALL ACROSS THE
WESTERN AND CENTRAL OKLAHOMA AND TEXAS PANHANDLES SHOULD BE ON ALERT
FOR POSSIBLE ACTIVATION LATER TODAY THROUGH TONIGHT.

SCHNEIDER