FXUS63 KOAX 131611
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1111 AM CDT MON JUN 13 2011
.DISCUSSION...
MADE SOME MINOR CHANGES TO THE FORECAST TODAY BASED ON CURRENT
TRENDS AND THE MORNING UPPER AIR ANALYSIS.
CURRENT RADAR MOSAIC INDICATES THAT NOCTURNAL MCS IS NOW MOVING
EAST OUT OF OUR FORECAST AREA INTO IOWA. OUTFLOW BOUNDARY FROM
MCS WAS CONTINUING TO MOVE TO THE SOUTH AND AS OF 15Z EXTENDED
FROM NEAR AIO TO AFK TO BIE. TO THE NORTH OF THIS ADVANCING
BOUNDARY...STRATUS HAS DEVELOPED IN THE STABLE MOIST BOUNDARY
LAYER. WE EXPECT THIS OUTFLOW BOUNDARY TO CONTINUE TO MOVE TO THE
SOUTH INTO NORTHEAST KANSAS BEFORE STALLING.
THE ISSUE FOR THE DAY THEN BECOMES IF WE WILL SEE ANY
REDEVELOPMENT OF CONVECTION THIS AFTERNOON/EVENING. 12Z UPPER AIR
ANALYSIS INDICATED 50-60 KT H3 JET FROM CO INTO NM. THIS WAS
ASSOCIATED WITH A WEAK MID-LEVEL SHORTWAVE TROUGH NOTED AT 500 MB
WITH A COOL POCKET AND WEAK HEIGHT FALLS OVER COLORADO. STEEP MID-
LEVEL LAPSE RATES WERE NOTED OVER PARTS OF THE CENTRAL AND
SOUTHERN PLAINS WITH 500 TO 700 MB DELTA-T VALUES OF 20-26 C. THE
STRONGER EML SEEMS TO EXTEND FROM SOUTHERN NEB TO NORTHWEST MO AND
POINTS TO THE SOUTH. SIGNIFICANT LOW LEVEL MOISTURE WAS IN PLACE
THOUGH JUST NORTH OF AN 850 MB WARM FRONT OVER NEBRASKA. THIS MID-
LEVEL SHORT-WAVE WILL ADVANCE NORTHEAST TODAY AND SHOULD ALLOW FOR
SOME CONVECTION TO DEVELOP ALONG THE CURRENT FRONT FROM CENTRAL
SOUTH DAKOTA INTO WESTERN NEBRASKA. THIS MAY SNEAK INTO OUR
NORTHWEST FA THIS AFTERNOON AND SO WILL LEAVE SOME CHC POPS THERE.
THE OTHER AREA OF CONCERN WILL BE NEARED THE STALLED FRONT AT THE
KS/NEB BORDER. CURRENT FEELING IS THAT THERE ISN'T MUCH CHANCE
THAT STORMS WILL FIRE ALONG THIS BOUNDARY DURING THE DAYLIGHT
HOURS DUE TO THE STRENGTHENING CAP. WILL MAINTAIN A SCHC POP NEAR
THIS BOUNDARY THIS AFTERNOON AS THE LARGE-SCALE ENVIRONMENT
ISN'T COMPLETELY UNFAVORABLE FOR STORMS WITH A THE WEAK WAVE
MOVING INTO THE AREA.
OTHERWISE HAVE UPDATED TO LOWER HIGHS TODAY AND TO ADJUST
WINDS/CLOUDS BEHIND THE BOUNDARY.
NEW ZFP/GRIDS ARE ALREADY OUT.
BOUSTEAD
&&
.PREV DISCUSSION... /ISSUED 315 AM CDT MON JUN 13 2011/
DISCUSSION...
PRECIPITATION CHANCES OVER THE NEXT COUPLE OF DAYS CONTINUE TO BE
THE PRIMARY FORECAST CHALLENGE.
TAIL END OF MCS MOVING ACROSS THE NORTHERN PLAINS WAS RIDING THE
NEBRASKA SOUTH DAKOTA BORDER THIS MORNING...AND HAS RECENTLY
EXHIBITED A GRADUAL TURN TO THE SOUTHEAST INTO MODEST LOW LEVEL JET.
THIS ACTIVITY WILL AFFECT NORTHEAST NEBRASKA EARLY THIS
MORNING...AND EVENTUALLY ROLL THROUGH WEST CENTRAL IOWA AS LOW LEVEL
JET MAINTAINS CONVECTION THIS MORNING. TO THE SOUTH...MID LEVEL WARM
ADVECTION REGIME WAS TRYING TO SPARK CONVECTION IN NORTH CENTRAL AND
NORTHEAST KANSAS AS MODELS HAVE ADVERTISED OVER THE LAST COUPLE OF
DAYS...WITH 00Z MODELS NO DIFFERENT. 40KT LOW LEVEL JET WAS FEEDING
THIS AREA...SO COULD STILL SEE SOME STORMS ROLL THROUGH SOUTHEAST
NEBRASKA THIS MORNING.
ATTENTION THEN TURNS TO UPPER WAVE RIDING INTO WESTERN COLORADO THIS
MORNING. MID LEVEL FLOW TAKES THIS WAVE INTO NORTHERN NEBRASKA THIS
AFTERNOON AND EVENING. MEANWHILE...WARM FRONT CURRENTLY IN SOUTHERN
KANSAS WILL LIFT NORTH INTO AT LEAST NORTHEAST KANSAS AND NORTHWEST
MISSOURI. DEW POINTS IN THE UPPER 60S TO NEAR 70 UNDER COOLING MID
LEVEL TEMPS WILL YIELD CAPES OVER 3000 J/KG WITH NEARLY 40 KTS OF
0-6KM BULK SHEAR. INHIBITION SHOULD ERODE BY LATE AFTERNOON ALLOWING
CONVECTION TO FIRE ALONG AND NORTH OF WARM FRONT FROM NORTHEAST
KANSAS INTO SOUTHEAST NEBRASKA. CONTINUED DEVELOPMENT NORTHEAST INTO
SOUTHWEST IOWA WILL ENSUE AS SOUTHWEST 40KT LOW LEVEL JET RIDES OVER
FRONTAL ZONE. SPC PAINTS THIS PART OF OUR CWA IN A 5 PERCENT TORNADO
RISK LATE THIS AFTERNOON AND EVENING. MODELS INDICATE LOW LEVEL
SHEAR ALONG WARM FRONT WILL REMAIN SOUTH OF OUR AREA...BUT THERE IS
SOME INDICATION THAT BOUNDARY WILL NOSE INTO OUR FAR SOUTHEAST CWA
DURING THE EVENING. WILL OUTLINE THIS POSSIBILITY IN OUR HAZARDOUS
WEATHER OUTLOOK THIS MORNING.
CONVECTION WILL GRADUALLY WORK EAST DURING THE EVENING. HOWEVER
ANOTHER AND SOMEWHAT STRONGER MID LEVEL WAVE WILL MOVE INTO THE
PLAINS ON TUESDAY. SURFACE FRONT SHOULD BE SUPPRESSED SOUTH AFTER
MONDAY EVENING CONVECTION...BUT COOL TEMPS ALOFT SUGGEST SCATTERED
SHOWER OR THUNDERSTORMS WILL LIKELY DEVELOP ON TUESDAY. THESE WILL
AGAIN MOVE EAST OF THE AREA DURING THE LATE EVENING.
A DRY PERIOD STILL LOOKS ON TRACK WEDNESDAY INTO THURSDAY AS MID
LEVEL RIDGING PUSHES STORM TRACK AWAY FROM EASTERN NEBRASKA AND
WESTERN IOWA. HIGH TEMPERATURES SHOULD REBOUND BACK INTO THE 80S FOR
ALL OF THE AREA THEN.
HAVE NOT CHANGED THE FORECAST BEYOND THURSDAY. ANOTHER SYSTEM IS
FORECAST INTO THE REGION THURSDAY NIGHT WITH ATTENDANT WARM
ADVECTION SUGGESTING THUNDERSTORM DEVELOPMENT THURSDAY NIGHT INTO
FRIDAY. THE WEEKEND FORECAST REMAINS MURKY WITH MODELS SHOWING
VARIOUS SOLUTIONS TO VARIOUS SHORTWAVES RIDING THROUGH SOUTHWEST
FLOW ALOFT.
DERGAN
AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
WEATHER FEATURES AFFECTING THE AREA ARE SHORTWAVE TROUGH ENERGY
MOVING ACROSS THE CENTRAL AND NORTHERN PLAINS...AND AN AREA OF LOW
PRESSURE OVER SOUTHWEST KANSAS WITH A STATIONARY FRONT ACROSS
SOUTHERN KANSAS. THUNDERSTORMS HAVE BEEN ONGOING ALL NIGHT AND HAVE
BEEN PUSHING ACROSS THE DAKOTAS. A CLUSTER OF STRONG STORMS HAVE
BEEN TRACKING EAST SOUTHEAST INTO NORTH CENTRAL NEBRASKA. ALTHOUGH
THE BETTER LIFT IS NORTH OF THE AREA...PROPAGATION VECTORS HAVE A
SOUTHEAST THEN A EAST MOVEMENT TO THEM AND WITH THE MOISTURE AXIS
AND THETA-E ADVECTION INTO EASTERN NEBRASKA THUNDERSTORMS MAY AFFECT
THE KOFK TAF THIS MORNING. ACCAS CLOUDS WERE NOTED ON SATELLITE FROM
CENTRAL NEBRASKA AND KANSAS INTO EASTERN NEBRASKA AND MISSOURI WITH
A GRADIENT IN H85 TEMPS IN THIS AREA. THE LOW LEVEL JET IS FCST TO
STRENGTHEN OVER NORTHEAST KANSAS. WITH DEEP MOISTURE IN
PLACE...WILL NEED TO MONITOR TSRA DEVELOPMENT THIS MORNING AS DO NOT
HAVE THEM GETTING INTO KLNK/KOMA. LOW CLOUDS SHOULD CONTINUE TO
DEVELOP THIS MORNING THUS MVFR CIGS INCLUDED THROUGH THE MORNING.
THESE MAY LIFT TO VFR THIS AFTERNOON...THEN RETURN TO MVFR TONIGHT.
DEPENDING ON THE HEATING AND FORCING THIS AFTERNOON...STRONG TSRA
MAY DEVELOP THIS AFTERNOON AND TONIGHT. DUE TO UNCERTAINTY DO NOT
HAVE IN CURRENT FCST...HOWEVER WILL LOOK AT PROB30 WITH NEXT
ISSUANCE. SOUTHEAST TO EAST WINDS DURING THE PERIOD GENERALLY FM 8
TO 15KTS.
ZAPOTOCNY
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$