Monday, May 7, 2007

DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 070556
SWODY1
SPC AC 070553

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1253 AM CDT MON MAY 07 2007

VALID 071200Z - 081200Z

..THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE CNTRL PLAINS
SWWD TO THE SRN HIGH PLAINS...

..UPR GRTLKS SWWD TO THE SRN HIGH PLAINS...
THE UPR TROUGH OVER THE WRN STATES WILL UNDERGO SUBTLE TRANSITION
EARLY THIS WEEK. A STRONG SHORTWAVE TROUGH NOW OVER CO WILL LIFT
NWD AND BECOME ABSORBED IN THE POLAR WLYS...THEN EJECT EWD TOWARD
THE UPR GRTLKS LATER MONDAY. MEANWHILE...JET ENERGY DIGGING SWD
ALONG THE BACKSIDE OF THE TROUGH WILL CUT-OFF ANOTHER LOW OVER THE
DESERT SW BY MONDAY NIGHT. TO THE EAST...ANOMALOUS UPR LOW WILL DIG
THROUGH THE WRN ATLANTIC BASIN WITH A BACKDOOR COLD FRONT REACHING
THE MS RVR VLY MONDAY AFTN.

TSTMS WILL BE ONGOING AT THE START OF THE PERIOD WITHIN A BROAD
CONFLUENT SLY LLJ AXIS FROM OK NWD INTO THE UPR MS VLY. STRONGEST
PORTION OF THIS JET WILL TRANSLATE NEWD AS THE CO DISTURBANCE EJECTS
NEWD WITHIN THE NRN BRANCH. STORMS WILL LIKELY WEAKEN AS THEY HEAD
INTO THE UPR MS RVR VLY AND UPR GRTLKS OWING TO RELATIVELY DRY
LOW-LEVEL TRAJECTORIES.

MEANWHILE...SELY LOW-LEVEL FLOW WILL MAINTAIN UPPER 60S TO NEAR 70
DEG F SFC DEW POINTS FROM THE OZARKS SWWD INTO TX...ALONG/W OF THE
BACKDOOR FRONT AND AHEAD OF OUTFLOW BOUNDARIES/FRONT LEFT OVER FROM
NOCTURNAL CONVECTION. A SIZABLE REGION OF RATHER STEEP MID-LEVEL
LAPSE RATES EXISTS FROM PARTS OF SWRN TX NEWD INTO SWRN MO. THE
MAGNITUDE OF HEATING ACROSS THE OZARKS IS SOMEWHAT IN QUESTION GIVEN
THE EARLY DAY CONVECTIVE DEBRIS...BUT STRONGER HEATING SHOULD EXIST
FROM SWRN OK SWWD INTO W TX DURING THE AFTN. BY MID-AFTN...MLCAPES
WILL RANGE FROM 1000-2000 J/KG ACROSS PARTS OF THE OZARKS TO AOA
2000 J/KG FROM SWRN OK INTO SWRN TX.

TSTMS WILL LIKELY REDEVELOP OR STRENGTHEN FROM EXISTING STORMS IN
THE OZARKS REGION DURING THE AFTN WHERE CAP WILL REMAIN WEAK. H5
FLOW GRADUALLY WEAKENS ACROSS THIS AREA MONDAY AFTN...BUT SUFFICIENT
INSTABILITY WILL EXIST FOR LARGE HAIL/DAMAGING WIND GUSTS THROUGH
MID-EVENING.

THE PRIMARY SVR THREAT WILL GRADUALLY UNFOLD MONDAY AFTN/EVE FROM
PARTS OF OK SWWD INTO W TX. TSTMS SHOULD INITIATE ALONG
BOUNDARIES/WRN EDGE OF PRIMARY LOW-LEVEL MOISTURE RETURN FROM THE
DAVIS MOUNTAINS AREA AND EXPAND/DEVELOP NEWD. HERE...H5 FLOW WILL
BE STRONGER GIVEN THE CLOSE PROXIMITY OF THE UPR TROUGH...ROUGHLY
50-60 KTS. AS A RESULT...SUPERCELLS WILL BE POSSIBLE WITH LARGE
HAIL AND ISOLD TORNADOES. ACTIVITY WILL LIKELY EVOLVE INTO SEVERAL
TSTM CLUSTERS BY EVENING. SET-UP WILL BE FAVORABLE FOR TSTMS TO
BACKBUILD SWWD INTO SWRN TX THROUGH THE NIGHT WITH HEAVY RAINFALL
AND LARGE HAIL. AT THE SAME TIME...WSWLY FLOW ALOFT WILL BE
CONDUCIVE FOR COLD POOLS TO ELONGATE ENEWD WITH POSSIBLE DAMAGING
WINDS IN ADDITION TO THE NOCTURNAL HAIL THREAT.

FINALLY...THERE WILL LIKELY BE SOME INCREASE IN LOW-LEVEL MOISTURE
AS FAR W AS SERN NM/FAR W TX MONDAY NIGHT. TSTMS MAY FORM THIS FAR
WEST AND/OR MOVE NWD FROM MEXICO. THESE STORMS WILL POSE A DAMAGING
WIND/HAIL THREAT.

.RACY/GRAMS.. 05/07/2007

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