Flooding in Nebraska, February 20 to 27, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
420 AM CST TUE FEB 20 2007

.DISCUSSION...WARM TEMPERATURES TO CONTINUE THE NEXT SEVERAL DAYS
AHEAD OF A POTENT WEEKEND STORM SYSTEM.

A SWATH OF LIGHT RAIN AND SNOW ASSOCIATED WITH A MID-LEVEL SHORTWAVE
AND ASSOCIATED BAND OF H7 FRONTOGENESIS CONTINUED TO SKIRT EAST
ACROSS THE CWA EARLY THIS MORNING. THE AREA OF ANY POTENTIALLY
MEASURABLE PRECIPITATION WAS CONFINED TO THE EASTERN TIER OF NE
COUNTIES AS OF 0930Z AND SHOULD CONTINUE TO PUSH EAST OUT OF THE CWA
WITHIN THE NEXT HOUR. CLOUDS WILL BE SLOWER TO CLEAR...BUT SHOULD
SEE A STEADY REDUCTION IN SKY COVER FROM NORTHWEST TO SOUTHEAST
THROUGH THE MORNING. FOG HAS BEEN DEVELOPING ON THE BACK EDGE OF THE
CLEARING LINE TO OUR WEST. NAM12 LOW-LEVEL RH FIELDS SEEM TO HAVE A
DECENT HANDLE ON THIS...AND SHOW FOG SPREADING ACROSS ROUGHLY THE
NORTHERN HALF OF THE CWA THIS MORNING...AND HAVE INCLUDED THIS IN THE
GRIDS FOR THIS AREA THROUGH MID MORNING.

IN WAKE OF THE FAST-MOVING MID-LEVEL WAVE...A FAIRLY QUIET BUT WARM
PATTERN WILL SET IN FOR THE NEXT FEW DAYS. THE UPPER FLOW WILL
GRADUALLY BECOME MORE ZONAL TODAY INTO TONIGHT...WHILE SURFACE WINDS
STEADILY BACK EVENTUALLY BECOMING SOUTHWESTERLY BY LATE IN THE
DAY. MAX TEMPS SHOULD GENERALLY BE SIMILAR TO THOSE ATTAINED
YESTERDAY IN THE UPPER 40S TO LOWER 50S. A ZONAL FLOW CONTINUES
ALOFT ON WEDNESDAY...AND THIS LOOKS TO BE THE WARMEST DAY OF THE
WEEK. H85 TEMPS ARE PROGGED TO RANGE FROM 4C IN THE NORTHEAST TO
9C IN THE SOUTHWEST...WITH FORECAST SOUNDINGS SHOWING DEEPER
MIXING TO JUST ABOVE THE H85 LEVEL. THIS IN COMBINATION WITH
COMPRESSIONAL WARMING FROM WESTERLY DOWNSLOPE WINDS AND PLENTY OF
SUNSHINE SHOULD DRIVE TEMPS INTO THE MID 50S TO LOWER 60S. A
NORTHERN PLAINS WAVE SENDS A WEAK BOUNDARY INTO THE CWA DURING THE
AFTERNOON...BUT WILL NOT HAVE MUCH EFFECT ON TEMPS. WINDS DROP OFF
WEDNESDAY NIGHT AS A SURFACE RIDGE AXIS PASSES OVER THE AREA...AND
WITH CLEAR SKIES WE MAY END UP SEEING SOME FOG DEVELOP IN AREAS
WHERE SIGNIFICANT MELTING OCCURS DURING THE DAY ON WEDNESDAY. DID
NOT INCLUDE ANY FOG YET...BUT WILL BE SOMETHING TO KEEP AN EYE ON.

THE UPPER RIDGE AMPLIFIES ON THURSDAY AS A STRONG UPPER LOW NEARS
THE WEST COAST. HEIGHT FALLS IN THE LEE OF THE ROCKIES WILL INDUCE A
SURFACE TROUGH...WITH SURFACE WINDS TURNING SOUTHEAST IN BETWEEN THE
DEEPENING LEE TROUGH AND AN ELONGATED RIDGE THROUGH THE MISSISSIPPI
VALLEY. THIS CHANGE TO A LESS FAVORABLE WIND DIRECTION FOR WARMING
IN COMBINATION WITH REDUCED MIXING TO AROUND 900MB WILL RESULT IN
SLIGHTLY COOLER TEMPS THAN EXPECTED ON WEDNESDAY.

IN THE EXTENDED PERIOD...A STRONG SYSTEM IS STILL ON TRACK TO IMPACT
THE REGION THIS WEEKEND. THE GULF OF MEXICO WILL BE WIDE OPEN AND
SOUTHERLY FLOW WILL BEGIN TO ADVECT AMPLE MOISTURE INTO THE REGION
ON FRIDAY. OPERATIONAL RUNS OF THE GFS AND ECMWF REMAIN IN GOOD
AGREEMENT WITH THE OVERALL TRACK OF THE LOW...WHICH WILL PUT US IN A
FAVORABLE POSITION TO RECEIVE SOME SUBSTANTIAL PRECIPITATION. IT
LOOKS LIKE RAIN WILL TURN TO SNOW SATURDAY AFTERNOON INTO SATURDAY
EVENING...WITH SNOW CONTINUING INTO SUNDAY BEFORE TAPERING OFF FROM
WEST TO EAST LATER IN THE DAY. STRONG WINDS ARE EXPECTED SATURDAY
EVENING INTO MIDDAY SUNDAY IN THE NORTHWEST QUADRANT OF THE SURFACE
LOW...AND IF CURRENT MODEL TRENDS HOLD...BLIZZARD CONDITIONS COULD
DEVELOP DURING THIS TIME ALONG WITH SIGNIFICANT SNOW ACCUMULATIONS.
OF COURSE THIS IS STILL SEVERAL DAYS OUT BUT WILL OBVIOUSLY BEAR
CLOSE WATCHING OVER THE NEXT SEVERAL DAYS.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

KB

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HASTINGS NE
525 AM CST TUE FEB 20 2007

KSZ005>007-017>019-NEZ039>041-046>049-060>064-072>077-082>087-
211200-
PHILLIPS-SMITH-JEWELL-ROOKS-OSBORNE-MITCHELL-VALLEY-GREELEY-NANCE-
SHERMAN-HOWARD-MERRICK-POLK-DAWSON-BUFFALO-HALL-HAMILTON-YORK-
GOSPER-PHELPS-KEARNEY-ADAMS-CLAY-FILLMORE-FURNAS-HARLAN-FRANKLIN-
WEBSTER-NUCKOLLS-THAYER-
525 AM CST TUE FEB 20 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL NEBRASKA AND
PORTIONS OF NORTH CENTRAL KANSAS.

.DAY ONE...TODAY AND TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

A POTENT STORM SYSTEM IS EXPECTED TO IMPACT THE OUTLOOK AREA THIS
WEEKEND. LATEST INDICATIONS SUGGEST THAT RAIN WILL CHANGE TO SNOW
SATURDAY AFTERNOON INTO SATURDAY EVENING...WITH SNOW CONTINUING
SATURDAY NIGHT INTO SUNDAY...BEFORE TAPERING OFF LATER IN THE DAY
ON SUNDAY. SIGNIFICANT SNOWFALL ACCUMULATIONS ARE POSSIBLE FROM
LATE SATURDAY AFTERNOON INTO SUNDAY...ALONG WITH STRONG WINDS
CREATING BLOWING AND DRIFTING SNOW. THE EXACT TIMING AND TRACK OF
THE STORM ARE STILL UNCERTAIN...SO PLEASE STAY TUNED THROUGH THE
WEEK FOR THE LATEST UPDATES REGARDING THIS DEVELOPING STORM.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED THROUGH TONIGHT.

&&

MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING WEB PAGE:
   HTTP://WWW.WEATHER.GOV/HASTINGS  (ALL LOWERCASE)