Drought in Texas, April 1 to 30, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
938 PM CST FRI MAR 31 2006

.UPDATE...
ISOLATED SHOWERS AND A COUPLE OF THUNDERSTORMS HAVE BEEN POPPING
UP OCCASIONALLY THIS EVENING JUST SOUTHWEST OF OUR FORECAST AREA.
ONE SMALL LONE THUNDERSTORM IS JUST NOW ENTERING WESTERN KNOX
COUNTY. AS A RESULT OF THIS ACTIVITY... WE WILL REMOVE THE PRE-
MIDNIGHT /LACK OF/ POPS.

MODELS DIFFER IN THEIR ESTIMATE OF WHERE OVERNIGHT RAIN WILL BE.
IT MAKES THE MOST SENSE... HOWEVER... FOR THE STORMS TO FORM NEAR
AND NORTH OF THE WEAK SURFACE BOUNDARY THAT IS NOW STUCK IN
SOUTHEAST OKLAHOMA AND INTO TEXAS NEAR ABILENE. LOW-LEVEL AIR
NORTH OF THE FRONT IS AWFULLY DRY... SO IT WILL BE DIFFICULT TO
GET MUCH IN THE WAY OF RAIN OUT OF THE SMALLER STORMS THIS
EVENING. IT ALSO SEEMS QUITE IMPROBABLE THAT ANY STORMS WILL BE
CAPABLE OF ANYTHING MORE THAN MARGINAL SEVERE HAIL TONIGHT.
TOMORROW... OF COURSE... IS A DIFFERENT STORY.

&&

.PREV DISCUSSION... (ISSUED 330 PM CST FRI MAR 31 2006)

DISCUSSION...ACTIVE SPRING PATTERN WILL CONTINUE TO FOCUS OUR
ATTENTION ON THUNDERSTORMS AND SEVERE WEATHER THIS WEEKEND.
PERSISTENT SOUTHEASTERLY GRADIENT FLOW OFF THE GULF HAS BROUGHT
MIXING RATIOS UP TO AROUND 15 G/KG ALONG THE COAST...WITH 11 TO 12
G/KG FARTHER NORTH AND WEST. MID LEVEL LAPSE RATES WERE SUPPRESSED
SOMEWHAT BY SUBSIDENCE IN WAKE OF GREAT LAKES SYSTEM...BUT WILL
STEEPEN AGAIN AS SOUTHWEST FLOW RETURNS ALOFT. AIR MASS IS...IN
FACT...WEAKLY CAPPED THIS AFTERNOON ALONG WEAK FRONTAL BOUNDARY IN
SOUTH CENTRAL OKLAHOMA. WILL CARRY SLIGHT POPS INTO THE EVENING
ALONG THE FRONT...ALTHOUGH ANY SEVERE SHOULD BE VERY ISOLATED.

ACTIVITY EXPECTED TO INCREASE AFTER MIDNIGHT WITH APPROACH OF
MID/UPPER LEVEL WAVE...WHICH WATER VAPOR SHOWED FROM NEW MEXICO INTO
NORTHERN MEXICO. VERTICAL CIRCULATION WITH THIS FEATURE DOES NOT
APPEAR VERY STRONG IN CROSS SECTIONS...BUT BOTH NAM/GFS SOUNDINGS
BECOME SATURATED AND UNSTABLE IN THE FRONTAL ZONE. WENT WITH THE
MORE REASONABLE MET MOS POPS WHICH WERE ALSO CONSISTENT WITH
PREVIOUS FORECAST. POTENTIAL FOR SOME HAIL OVERNIGHT.

SATURDAY WILL SEE COMPLEX EVOLUTION OF UPPER LEVEL AND SURFACE
FEATURES...BUT SEVERE WEATHER EVENT APPEARS LIKELY TO CONGEAL ALONG
THE DRYLINE IN WESTERN OKLAHOMA BY LATE AFTERNOON AND EVENING. EARLY
MORNING ACTIVITY WILL SPREAD THROUGH CENTRAL AND EASTERN OKLAHOMA BY
NOON...POSSIBLY REINFORCING AN OUTFLOW BOUNDARY OR DIFFERENTIAL
HEATING BOUNDARY IN SOUTHERN OKLAHOMA...WHILE THE SYNOPTIC FRONT
LIFTS NORTH INTO KANSAS. BOTH OF THESE BOUNDARIES HINTED AT IN
NAM SURFACE PRESSURE AND 1000-700MB THICKNESS FIELDS.
STRENGTHENING LOW LEVEL FLOW FORECAST TO BRING IN A BROAD WARM
SECTOR WITH DEWPOINTS IN THE 60S. MODEL SOLUTIONS DIVERGE AFTER
NOON...BUT MORE CONSISTENT AND BETTER INITIALIZED UKMET INDICATES
CYCLOGENESIS OVER EASTERN COLORADO...WITH A WELL TIMED 700 MB
SHORTWAVE TROF APPROACHING THE DRYLINE AT 00Z. THIS ALONG WITH
PERSISTENT QPF SIGNAL FROM ETA AND GFS LEND CONFIDENCE THAT
SCATTERED STORMS WILL FORM ON THE DRYLINE AND MOVE EAST OVERNIGHT.
MODERATE INSTABILITY AND STRONG WIND SHEAR SUPPORT A MODERATE RISK
FOR SEVERE WEATHER. MAINTAINED CHANCE POPS...HOWEVER...WITH MAIN
WAVE HANGING BACK UNTIL SUNDAY MORNING...AND INITIAL WAVE FAVORING
SCATTERED DISCRETE CELLS. EXCEPTION MAY BE ON THE NOSE OF THE LOW
LEVEL JET SATURDAY NIGHT ACROSS NORTH CENTRAL OKLAHOMA...WHERE
AREAL COVERAGE MAY INCREASE.

MODEL TIMING DIVERGES EVEN MORE ON SUNDAY...BUT WILL AGAIN FAVOR THE
SLOWER UKMET SOLUTION...GIVEN THE FAVORABLE ENVIRONMENT FOR
CYCLOGENESIS. THIS SHOULD PLACE AT LEAST THE PART OF CENTRAL AND
SOUTHEAST OKLAHOMA AT RISK FOR SEVERE STORMS EARLY SUNDAY. BIGGER
STORY COULD BE FIRE WEATHER BEHIND THE DRYLINE...WITH TEMPERATURES
RISING TO NEAR 80 AND LOW HUMIDITY. SUSPECT THE WINDS WILL BE
STRONGER THAN CURRENT MODEL GUIDANCE...BUT PERHAPS NOT EXTREME
BECAUSE THE STORM WILL BE PULLING AWAY DURING THE DAY. CURRENT
SPREAD INDICES SUGGEST VERY HIGH FIRE DANGER IN WEST/NORTHWEST
OKLAHOMA.

THE NEXT WEAK COLD FRONT STALLS IN CENTRAL TEXAS MONDAY WHILE THE
NEXT SYSTEM STARTS TO DIG INTO THE WEST. ANOTHER ROUND OF RETURN
MOISTURE FOLLOWED BY A DRYLINE SURGE WILL BE POSSIBLE TUESDAY
THROUGH THURSDAY OF NEXT WEEK. INCREASED POPS SOMEWHAT DURING THIS
PERIOD.

TEMPERATURES GENERALLY 70S AND LOWER 80S THROUGHOUT THE FORECAST.

&&

.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK  56  79  63  81 /  20  30  40  40
HOBART OK         55  82  56  83 /  20  30  40  10
WICHITA FALLS TX  59  83  63  84 /  30  30  40  40
GAGE OK           49  81  50  79 /  10  40  40  10
PONCA CITY OK     48  77  62  79 /  10  30  50  40
DURANT OK         62  79  67  81 /  40  40  40  60

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&

23/32

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE NORMAN OK
735 PM CST FRI MAR 31 2006

OKZ004>048-050>052-TXZ083>090-011300-
HARPER-WOODS-ALFALFA-GRANT-KAY-ELLIS-WOODWARD-MAJOR-GARFIELD-NOBLE-
ROGER MILLS-DEWEY-CUSTER-BLAINE-KINGFISHER-LOGAN-PAYNE-BECKHAM-
WASHITA-CADDO-CANADIAN-OKLAHOMA-LINCOLN-GRADY-MCCLAIN-CLEVELAND-
POTTAWATOMIE-SEMINOLE-HUGHES-HARMON-GREER-KIOWA-JACKSON-TILLMAN-
COMANCHE-STEPHENS-GARVIN-MURRAY-PONTOTOC-COAL-COTTON-JEFFERSON-
CARTER-JOHNSTON-ATOKA-LOVE-MARSHALL-BRYAN-HARDEMAN-FOARD-WILBARGER-
WICHITA-KNOX-BAYLOR-ARCHER-CLAY-
735 PM CST FRI MAR 31 2006

THIS HAZARDOUS WEATHER OUTLOOK COVERS NORTHERN...WESTERN...
CENTRAL...AND SOUTHERN OKLAHOMA...AND WESTERN NORTH TEXAS.

.DAY ONE...TONIGHT...

THUNDERSTORM OUTLOOK...
A FEW THUNDERSTORMS WILL BE POSSIBLE LATE TONIGHT ACROSS CENTRAL AND
SOUTHERN OKLAHOMA AND WESTERN NORTH TEXAS. ALTHOUGH NO ORGANIZED
SEVERE WEATHER IS EXPECTED... A FEW OF THE STORMS COULD APPROACH
SEVERE LEVELS.

DISCUSSION...
A STATIONARY FRONT EXTENDING FROM SOUTHEAST OKLAHOMA INTO NORTH
TEXAS WILL BEGIN TO LIFT BACK TO THE NORTH OVERNIGHT... INCREASING
THE CHANCE FOR THUNDERSTORMS ACROSS NORTH TEXAS AND SOUTHERN
OKLAHOMA. A FEW OF THESE STORMS MAY APPROACH OR MARGINALLY SURPASS
SEVERE LIMITS.

PROBABILITY TABLE...
VALID THROUGH 700 AM CST SATURDAY APR 1.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...50 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR...20 PERCENT.

OTHER HAZARDOUS WEATHER...
NONE.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY...

THUNDERSTORM OUTLOOK...
THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS SATURDAY ACROSS
WESTERN OKLAHOMA AND WESTERN NORTH TEXAS AND A SLIGHT RISK OF SEVERE
THUNDERSTORMS OVER THE REMAINDER OF THE AREA EAST OF THE MODERATE
RISK AREA.  A WARM FRONT LOCATED ACROSS CENTRAL OKLAHOMA EARLY IN
THE DAY WILL LIFT NORTHWARD INTO KANSAS BY SATURDAY AFTERNOON.  IN
THE MEANTIME...A DRYLINE WILL PUSH INTO THE EASTERN TEXAS PANHANDLE
AHEAD OF AN UPPER LEVEL SYSTEM.  THUNDERSTORMS...SOME SEVERE...ARE
EXPECTED TO DEVELOP IN THE MODERATE RISK AREA SATURDAY AFTERNOON AND
EVENING WITH THE STORMS MOVING INTO THE SLIGHT RISK AREA LATER IN
THE NIGHT. STORM SPOTTERS ARE URGED TO KEEP UPDATED WITH THE LATEST
FORECASTS AND BE PREPARED FOR POSSIBLE ACTIVATION ON SATURDAY.

OTHER HAZARDOUS WEATHER...
NONE.

CJS