FXUS63 KOAX 282144
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
344 PM CST FRI JAN 28 2011
.SHORT TERM...TONIGHT THROUGH MONDAY.
SOMEWHAT COMPLICATED SITUATION DEVELOPING TOWARD THE END OF THIS
FORECAST PERIOD WITH STOUT ARCTIC BLAST AND POSSIBLE SNOW/SLEET MIX.
LARGE SCALE FLOW GRADUALLY ALTERING TO HIGHLY AMPLIFIED WEST COAST
RIDGE BY THE END OF THIS WEEKEND WITH DIGGING POSITIVE TILT TROF OVER
THE WESTERN STATES. BEFORE THE LARGE SCALE TRANSITION...EMBEDDED VORT
MAX WITHIN NORTHWEST FLOW ALOFT AND ASSOCIATED CLIPPER TYPE LOW WILL
EXIT THE UPPER MIDWEST AND PUSH TO OHIO VALLEY EARLY SATURDAY MORNING
BRINGING INITIAL SURGE OF ANTICIPATED COLD AIR ADVECTION TO THE
CENTRAL PLAINS. SEEMS TO BE SMALL CHANCE FOR LIGHT SNOW NORTH BY
AFTERNOON WHEN VORT ENERGY OVER SOUTHERN ROCKIES INDUCES SURFACE
CYCLOGENESIS NEAR OK/TX PANHANDLE AND FORCES WAA NORTHWARD WITH
NEARLY STATIONARY THERMAL BOUNDARY SETTING UP FROM ABOUT WESTERN KS
TO MO. THE POSSIBLE LIGHT SNOW DEVELOPMENT WILL COME VIA STRONG 295K
UPGLIDE EXTENDING NORTHWARD INTO THE DAKOTAS...COUPLED WITH WEAK VORT
MAX OVERHEAD ALONG WITH BETTER MOISTURE TO TAP INTO. ON SUNDAY
REINFORCING SHOT OF COLD AIR SINKS SOUTHWARD INTO NEB/IA. STILL
APPEARS THAT THE NRN CWA WILL SEE BEST CHANCE FOR ANY SNOW
DEVELOPMENT IN THE AFTERNOON/SUNDAY NIGHT TIME FRAME. 295K UPGLIDE
REMAINS STRONG OVER THE AREA BUT LOWEST COND PRES DEF REMAIN FOCUSED
OVER THE NRN SECTIONS OF CWA/DAKOTAS. ALSO PRECIP TYPE MAY BECOME AN
ISSUE OVER AREAS SOUTH OF I-80 LATE SUNDAY NIGHT AND MONDAY. DECENT
AGREEMENT PER SOUNDING/CRITICAL THICKNESSES PROGS FOR SNOW/SLEET MIX
DEVELOPING. OTHERWISE COLD...COLD ...COLD HEADING INTO NEXT WEEK
WITH HIGHS STRUGGLING TO REACH THE LOW/MID TEENS ON MONDAY.
DEE
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY.
COMPLEX WEATHER FORECAST IN THE EXTENDED FORECAST. BOTH GFS AND THE
ECMWF DIFFER IN SOLUTIONS TO SHORT WAVE ENERGY DROPPING SOUTHWARD
INTO THE CONTINENTAL US MONDAY INTO WEDNESDAY. ECMWF CUTS OFF UPPER
AIR LOW PRESSURE SYSTEM OVER THE INTERMOUNTAIN REGION OF THE US ON
TUESDAY...WHILE THE GFS IS SLOWER AND WHILE IT CUTS OFF THE UPPER
LOW OUT WEST...IT HAS A MORE DOMINANT NORTHERN STREAM WAVE. THE
ECMWF THEN NEGATIVELY TILTS OUT A TROUGH ACROSS THE CENTRAL AND
SOUTHERN PLAINS. THIS ALLOWS FOR THE SURFACE LOW PRESSURE SYSTEM TO
MOVE FURTHER NORTH THAN THE GFS SOLUTION. THIS WOULD PUT EASTERN
NEBRASKA AND SOUTHWEST IOWA IN THE DEFORMATION BAND OF SNOW ON
TUESDAY NIGHT. AT THIS TIME...PREFER THE SLOWER GFS SOLUTION WITH A
SURFACE LOW TRACK FURTHER SOUTH.
ISENTROPIC LIFT AT 285K ON MONDAY NIGHT REVELS A LARGE AREA OF LIFT
ACROSS EASTERN NEBRASKA INTO IOWA. THE AREA ISENTROPIC LIFT IS
EXPECTED TO SHIFT TO SOUTHEAST NEBRASKA AND SOUTHWESTERN IOWA DURING
THE DAY TUESDAY. SNOW THEN SHOULD BEGIN TO TAPER OFF ON WEDNESDAY
MORNING. ANOTHER COLD FRONT WITH REINFORCING ARCTIC AIR IS EXPECTED
TO MOVE THROUGH THURSDAY NIGHT INTO FRIDAY.
SMITH
&&
.AVIATION...
18Z TAFS
VISUAL FLIGHT RULE CONDITIONS ARE EXPECTED AT KOFK/KLNK THROUGH THE
PERIOD. SAME CONDITIONS AT KOMA UNTIL ABOUT 06Z WHEN SOME MARGINAL
FLIGHT RULE FOG COULD DEVELOP...AND IF IT DOES...COULD LINGER
THROUGH ABOUT 29/15Z.
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$