FXUS63 KOAX 251955
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
255 PM CDT MON APR 25 2011
.SHORT TERM...TONIGHT
SHORT TERM CONCERN WILL BE PRECIPITATION THROUGH TONIGHT.
A MID TROPOSPHERIC TROUGH FROM MONTANA THROUGH THE PLAINS STATES
WILL CONTINUE TO SWING THROUGH THE REGION OVERNIGHT. LOWER LEVEL
AND MID LEVEL WARM AIR ADVECTION IS UNDERWAY ALONG WITH SOME GOOD
H850 THETA-ADVECTION. UPWARD VERTICAL MOTION ASSOCIATED WITH THE
TROUGH IS STRONGEST THROUGH 06Z...THEN SHIFTS TO NORTHEAST NEBRASKA
BY 12Z. THE PRECIPITATION HAD EXPANDED AND MOVED INTO THE FORECAST
AREA EARLIER TODAY. THE SHOWERS WILL CONTINUE THIS
EVENING...ALTHOUGH THERE WILL BE PERIODS OF LIGHTER PRECIPITATION
AND HEAVIER PRECIPITATION AS BETTER FORCING MOVES THROUGH PARTS OF
THE AREA. THERE ARE A FEW LIGHTNING STRIKES WEST OF CONCORDIA
KANSAS AND IS ON THE SOUTHEAST SIDE OF THE INFRARED SATELLITE
IMAGERY ENHANCEMENT. THERE COULD BE A FEW STRIKES THAT MAKE IT
INTO EASTERN NEBRASKA OR WESTERN IOWA. WILL LOOK AT CURRENT TRENDS
AND MAY ADD ISOLATED THUNDER TO THE FORECAST. EXPECT THE RAIN TO
BEGIN SHIFTING OUT OF THE FAR WESTERN AND SOUTHWEST PARTS OF THE
FORECAST AREA BY 06Z. TEMPERATURES OVERNIGHT SHOULD RANGE FROM THE
UPPER 30S WEST TO THE MID 40S EAST. NORTHEAST WINDS AT 5 TO 15 MPH
SHOULD COME AROUND TO THE NORTHWEST AT 10 TO 20 MPH AS SURFACE LOW
PRESSURE TRACKS TO THE SOUTH OF THE STATE.
.LONG TERM...TUESDAY THROUGH MONDAY.
PER 12Z GFS/NAM AND ECMWF MID LEVEL CIRCULATION CENTER BY 12Z
TUESDAY WILL BE EITHER IN WRN IA /NAM AND ECMWF/ OR ALONG WI/IA
BORDER /GFS/. WRN TWO SOLUTIONS WOULD POINT TO LINGERING RAIN NERN
ZONES TUE AM WHILE GFS WOULD PUT MOST IF NOT ALL OF THE WARM
CONVEYOR BELT/DEFORMATION PRECIP N OR E OF THE AREA. USING BLEND
WILL KEEP MODEST POPS IN NERN ZONE TAPERED OFF TO SLIGHT CHC IN
LINCOLN/OMAHA VICINITIES IN THE MORNING. QG FORCING FROM DEPARTING
LOW SHIFTS WELL WELL TO NE IN THE AFTERNOON WHILE FORECAST AREA
REMAINS NE OF FORCING ASSOCIATED WITH TRAILING WAVE THAT WILL BE
MOVING INTO KS. WOULD SUSPECT MUCH OF THE AREA IF NOT ALL WOULD BE
DRY IN THE AFTERNOON...BUT LEFT IN SMALL POPS FAR NE JUST IN CASE
A SLOWER SOLUTION EVOLVES. MORE NORTHERLY COMPONENT TO SURFACE
WINDS AND LONGER LIVED LOW CLOUD COVER COULD SPELL DIFFERENCE
BETWEEN MAX TEMPS STRUGGLING TO REACH 50 IN NE CORNER OF NEBRASKA
AND THOSE THAT COULD REACH LOWER 60S NEAR AND SW OF LINCOLN. MADE
LTL CHANGES TO PREVIOUS FORECAST WHICH WAS ON PESSIMISTIC SIDE
WITH UPPER 50S/AROUND 60 CONFINED TO ALONG AND SW OF A LINCOLN TO
FAR STOUTEST IOWA LINE.
BLOCKING EAST COAST PATTERN APPARENTLY WILL SEND OF PIECE OF
ENERGY AROUND STALLING UPPER LOW NE OF THE AREA WHICH SHOULD SEND
MORE LOW CLOUDS SWD ON WED. FOR THOSE AREAS THAT MANAGE TO CLEAR
OUT OF THEM THAT IS ON TUESDAY. THIS COULD KEEP TEMPS GENERALLY
BELOW GUIDANCE WHICH WAS TRYING TO LIFT NUMBERS TOWARD CLIMO. JUST
LEFT IN SMALL PRECIP CHCS FAR ERN COUNTIES CLOSER TO UPPER LOW.
WARMING STILL ON TRACK FOR THU/FRI PERIODS. 00Z ECMWF BACKED SURFACE
WINDS ACROSS THE NERN ZONES WHICH COULD INDICATE SHARPER WARM
FRONT DEVELOPING WHICH WOULD CREATE MORE OF TEMPERATURE RANGE
OVER THE CWA. HOWEVER...THIS WAS NOT FORECAST WITH 12Z RUN. THUS
BOOSTED TEMPERATURES A BIT...ESPECIALLY CENTRAL AND SOUTH. LEFT
IN SMALL POPS FRI NRN ZONES WITH MODEST CHC POPS STILL SUPPORTED
AS FRONT CROSSES THE AREA FRIDAY NIGHT.
GENERALLY COOLER WEATHER THEN NEXT WEEKEND/MONDAY...ALTHOUGH
CHANGES PROBABLY NECESSARY AS TIMING OF WEAK WAVES IN NWRLY UPPER
FLOW COULD BRING CHANGEABLE POPS AND IF APPROACH JUST
RIGHT...A BIT STRONGER WARM ADVECTION AND MIXING COULD BOOST
READINGS.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
MVFR/IFR CONDITIONS EXPECTED THROUGH THE OVERNIGHT HOURS AS A MID
LEVEL TROUGH SWINGS THROUGH THE FORECAST AREA. HAVE SHRA FROM NOW
THROUGH AROUND 06Z AT KOFK AND KOMA AND SHOULD END A COUPLE HOURS
EARLIER AT KLNK. PRECIPITATION COULD LINGER IN EASTERN AND WILL NEED
TO MONITOR LATER TONIGHT AND TUESDAY MORNING. THE RAIN INTENSITY
WILL BE VARIABLE AS THERE SHOULD BE PERIODS OF LIGHT RAIN AND
PERIODS OF MODERATE RAIN WITH SOME OF THE HEAVIER PRECIPITATION THAT
SWINGS THROUGH.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
CHERMOK/ZAPOTOCNY