FXUS63 KOAX 022157
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
ISSUED BY NATIONAL WEATHER SERVICE HASTINGS NE
357 PM CST WED MAR 2 2011
.DISCUSSION...A 1035MB SURFACE HIGH WAS CENTERED IN WISCONSIN EARLY
THIS AFTERNOON..WITH COOL EASTERLY LLVL IN PLACE ACROSS THE CENTRAL
PLAINS REGION. AFTN TEMPS HAVE RISEN TO THE UPPER 20S IN THE
NORTHERN CWA...TO READINGS NEAR 40 IN THE SOUTH...BUT STILL BELOW
SEASONAL NORMALS IN THE MID 40S.
AN AREA OF STRATUS HAD SETTLED ACROSS WESTERN KANSAS WITH THE
STRATUS AREA MORE PATCHY ACROSS WESTERN NEBRASKA. WATER VAPOR
IMAGERY INDICATES A SHORTWAVE TROUGH IN EASTERN COLORADO AND MODELS
ARE CONSISTENT IN TRANSLATING THE SYSTEM EASTWARD TONIGHT/THURSDAY
MORNING. ISENTROPIC LIFT INCREASES AHEAD OF THE APPROACHING WAVE
AS INDICATED ON THE 300K SURFACE. THE AREA OF STRATUS TO OUR WEST
IS EXPECTED TO EXPAND ACROSS EASTERN NEB/WESTERN IOWA THIS
EVENING/TONIGHT. THE INCREASING LIFT OVER THE STRATUS/LLVL
MOISTURE MAY GENERATE SOME LIGHT FREEZING DRIZZLE AS FORECAST
SOUNDINGS INDICATE DRY MID LEVELS AND LACK OF DENDRITIC MOISTURE.
HAVE INSERTED SOME LOW POPS TO ACCOUNT FOR THIS.
ANOTHER MID LEVEL SHORTWAVE TRANSLATES ACROSS THE DAKOTAS THURSDAY
NIGHT WITH AN ASSOCIATED COLD FRONTAL BOUNDARY PUSHING SOUTH THRU
THE NIGHT. DECENT MID LEVEL FRONTOGENESIS IS PROGGED BETWEEN H85
AND H7 ACROSS THE SOUTHERN HALF OF THE CWA. FORECAST SOUNDINGS
INDICATE DRY MID LEVELS WITH A WARM LAYER PRESENT AS WELL AND WITH
LOW TEMPS PROGGED NEAR OR BELOW FREEZING HAVE WENT WITH POTENTIAL OF
FZRA OR RAIN. THIS ROUND OF PCPN LOOKS TO WIND DOWN FAIRLY QUICKLY
ON FRIDAY WITH PCPN TYPE TRANSITIONING BACK TO RAIN AS TEMPS WARM
DURING THE DAY. HAVE KEPT FRIDAY NIGHT DRY AS LIFT FOCUSES TO OUR
SOUTH AND EAST.
OVER THE WEEKEND...IN A PROGRESSIVE PATTERN...A COUPLE OF SHORTWAVE
TROUGHS CROSS THE DAKOTAS WITH THE NORTHERN CWA ON THE SOUTHERN EDGE
OF ANY PCPN ACTIVITY SATURDAY NIGHT INTO SUNDAY....WITH CHCS
SPREADING SOUTH SUNDAY NIGHT INTO MONDAY. WITH THE APPROACHING
SYSTEMS...GOOD LIFT IS INDICATED ON THE 295K ISENTROPIC SURFACE.
ATTM...SNOW ACCUMULATION OVER THE WEEKEND LOOKS TO BE RATHER
LIGHT...WITH BETTER CHCS FOR ACCUMULATING SNOW ARRIVING NEXT
WEEK...DEPENDING ON THE TRACK OF THE SYSTEM.
AN UPPER TROUGH WILL STRENGTHEN OVER THE ROCKIES EARLY NEXT
WEEK...WITH THE LOW DEEPENING/CLOSING OFF AS IT EMERGES ONTO THE
PLAINS. MODELS ARE STILL NOT IN AGREEMENT ON THE TRACK OF THE
LOW...WITH THE ECMWF TAKING THE SYSTEM FM WESTERN NEBRASKA
NORTHEAST INTO EASTERN SOUTH DAKOTA...WHEREAS THE GFS HAS
MAINTAINED A FARTHER SOUTH SOLUTION WITH THE H7 LOW MOVING FM NW
KANSAS TOWARD NORTHEAST NEBRASKA. SIGNIFICANT SNOWFALL IS POSSIBLE
ACROSS THE MAJORITY OF THE CWA IF THE GFS SOLUTION
VERIFIES...WHEREAS THE NORTHERN ECWMF SOLUTION WOULD PROVIDE
LESSER PCPN AS THE AREA WILL BE UNDER THE DRY SLOT. FOR NOW HAVE
WENT WITH A MODEL BLEND BETWEEN THE SOLUTIONS AS THE POSITION OF
THE LOW AFFECTS HOW WARM TEMPS WILL BE AHEAD OF THE SYSTEM AND HOW
QUICKLY COLD AIR ARRIVES ON THE BACK SIDE OF THE SYSTEM. IN
ADDITION...MODELS INDICATE SOME INSTABILITY IN THE SOUTH TUESDAY
EVENING...AND HAVE INCLUDED SOME ISOLATED THUNDER. TRENDS OF THE
SYSTEM WILL CONTINUE TO BE MONITORED BUT IT IS DEFINITELY ONE TO
KEEP AN EYE ON.
&&
.AVIATION...CLOUDS WILL LOWER THIS EVENING AND TONIGHT AS AN AREA
OF STRATUS IN PORTIONS OF WESTERN KANSAS EXPANDS TO THE NORTH AND
EAST. CIGS ARE EXPECTED TO LOWER TO MVFR THIS EVENING...THE FALL
TO MAINLY IFR TONIGHT INTO THURSDAY MORNING. THERE IS SOME LIFT
EXPECTED OVER THE LOW CLOUDS AND SOME PATCHY FREEZING DRIZZLE MAY
DEVELOP BUT CHCS DO NOT APPEAR GREAT ENOUGH TO INCLUDE IN THE TAF
JUST YET AND WILL MONITOR TRENDS. VSBYS MAY DROP TO IFR AT TIMES.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
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