FXUS63 KOAX 201704
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1204 PM CDT SUN MAR 20 2011
.UPDATE...
ADJUSTED TEMPERATURES UPWARD AGAIN AND REDUCED POPS SOMEWHAT FOR TODAY
&&
.DISCUSSION...
UPDATED TO ACCOUNT FOR GUSTY SOUTHWEST WINDS/WARMER TEMPERATURES
ACROSS SOUTHEASTERN FORECAST AREA AND TO ALL TRIM BACK
PRECIPITATION CHANCES ALL BUT IA ZONES FOR THIS AFTERNOON. APPEARS
WITH WIND SHIFT/FRONTAL PASSAGE TIMING...SHOWER/THUNDERSTORM CHCS
PRETTY SMALL EXCEPT POSSIBLY NEAR FRONTAL LOCATION BY LATE
AFTERNOON. LOW CLOUD AREA CONTINUES TO SHRINK SLIGHTLY AS IT IS
SHOVED EAST BEHIND WIND SHIFT...AND WOULD EXPECT EVEN NORTHEASTERN
ZONES TO BECOME PARTLY OR MOSTLY SUNNY LATER THIS AFTERNOON. EVEN
RAISED TEMPERATURES A BIT THAT AREA DUE TO INCREASED MIXING EXPECTED.
CHERMOK
&&
.PREV DISCUSSION... /ISSUED 352 AM CDT SUN MAR 20 2011/
DISCUSSION...
TIMING THE HIGHEST CHANCES FOR SHOWERS AND THUNDERSTORMS OVER THE
NEXT FEW DAYS IS THE MAIN CONCERN.
LARGE SCALE MID TROPOSPHERIC PATTERN FEATURED A CLOSED LOW OFF THE
CALIFORNIA COAST AND A BROAD RIDGE FROM ONTARIO CANADA INTO THE
SOUTHEASTERN UNITED STATES. OUR AREA WAS IN SOUTHWEST FLOW...WITH
WATER VAPOR SATELLITE IMAGERY SHOWING SEVERAL DISTURBANCES IN THE
FLOW. 850 MB MOISTURE AT 00Z LAST EVENING WAS FAIRLY IMPRESSIVE
WITH A WEDGE OF 10 DEGREE CELSIUS DEWPOINTS FROM TEXAS UP INTO
SOUTHWEST KANSAS. IMPRESSIVE ISENTROPIC UPGLIDE WAS TAKING PLACE
EARLY THIS MORNING IN THE 290-305 KELVIN LAYER AND THE LOW LEVEL
JET HAD INCREASED TO AROUND 50 KNOTS PER THE FAIRBURY PROFILER.
SCATTERED SHOWERS AND THUNDERSTORMS SHOULD CONTINUE TO DEVELOP
THIS MORNING AHEAD OF A COLD FRONT THAT WILL BE PUSHING THROUGH
OUR AREA TODAY. THE 05Z RUN OF THE HRRR MODEL SEEMED TO HAVE A
DECENT HANDLE ON THE SITUATION. WILL KEEP PRECIPITATION CHANCES
MAINLY FROM 30 TO 50 PERCENT THIS MORNING AND 20 TO 30 PERCENT
THIS AFTERNOON. THE BETTER FOCUS THOUGH WILL BE SHIFTING EASTWARD
OUT OF OUR AREA AND WEAK HIGH PRESSURE SHOULD BE BUILDING IN. THE
MAXIMUM TEMPERATURE FORECAST FOR TODAY WILL BE TRICKY WITH
DECREASING CLOUD COVER AND NORTHWEST WINDS PROVIDING A DOWNSLOPE
COMPONENT AND MODEST MIXING POTENTIAL.
THE COLD FRONT THAT WILL PUSH THROUGH TODAY IS EXPECTED TO STALL TO
THE SOUTH ACROSS KANSAS AND MISSOURI...THEN START TO LIFT BACK TO
THE NORTH LATE TONIGHT AS LOW PRESSURE INTENSIFIES TO WEST.
ISENTROPIC UPGLIDE AND LOW LEVEL WINDS WILL INCREASE...PROVIDING
LIFT OVER THE BOUNDARY. KEPT PRECIPITATION CHANCES FOR LATE
TONIGHT JUST ACROSS THE FAR SOUTHERN PARTS OF SOUTHEAST NEBRASKA
FOR NOW. THE WARM FRONT SHOULD LIFT NORTHWARD INTO THE AREA
MONDAY AND MONDAY NIGHT...WITH HIGHEST PRECIPITATION CHANCES NORTH
OF THE FRONT. SOME SEVERE STORMS ARE POSSIBLE DURING THIS TIME AS
MOISTURE RETURNS AND LAPSE RATES INCREASE. AT THIS TIME...STAYED
SOMEWHAT CONSERVATIVE WITH HIGH TEMPERATURES MONDAY. EXPECT LOWER
AND MID 70S NEAR THE KANSAS AND MISSOURI BORDERS BUT ONLY AROUND
60 AT THE SOUTH DAKOTA BORDER. MOST OF THE LOCAL FORECAST AREA
REMAINS IN THE WARM SECTOR AHEAD MONDAY NIGHT AHEAD OF THE NEXT
COLD FRONT. LOWS WILL BE IN THE 40S NORTH AND LOWER TO MID 50S
SOUTH. SHOWER AND THUNDERSTORM CHANCES CONTINUE TUESDAY INTO EARLY
TUESDAY NIGHT UNTIL...DRIER AIR MOVES IN FROM THE WEST AND
NORTHWEST.
DID NOT MAKE MANY CHANGES TO THE FORECAST BEYOND WEDNESDAY. KEPT
A SLIGHT CHANCE OF RAIN OR SNOW NORTH WEDNESDAY. MODEL DIFFERENCES
BECOME FAIRLY LARGE BY NEXT WEEKEND...SO CONFIDENCE DROPS TO BELOW
AVERAGE FRIDAY AND SATURDAY.
AVIATION...
CURRENT IFR CONDITIONS AT KOFK AND KOMA SHOULD IMPROVE TO MVFR LATE
THIS MORNING OR EARLY AFTERNOON AND THE PROBABLY TO VFR THIS
AFTERNOON. LOW LEVEL WIND SHEAR IS ALSO EXPECTED TO CONTINUE INTO
MID MORNING. BEST THUNDERSTORM CHANCES APPEAR TO BE NORTH OF KOFK
AND SOUTHEAST OF BOTH KOMA AND KLNK BUT WILL UPDATE AS NEEDED.
SOUTHERLY WINDS WILL SHIFT TO THE WEST AND NORTHWEST LATER TODAY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
MILLER/ZAPOTOCNY