FXUS63 KOAX 191944
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
244 PM CDT TUE JUL 19 2011
.DISCUSSION...
ONE MORE DAY OF EXCESSIVE HEAT THEN SEVERAL WEAK FRONTAL PASSAGES
WILL BRING MORE CHANGEABLE WEATHER TO FORECAST AREA THROUGH THE
WEEKEND. UPPER RIDGE THAT HAS HELD FIRMLY IN PLACE SINCE LATE LAST
WEEK WILL BE FLATTENED BY AT LEAST 2 SHORTWAVE TROUGHS THAT WILL
CROSS THE NORTHERN PLAINS. FIRST TROUGH THAT WAS MOVING TOWARD
ERN WA/OR PER AFTERNOON WATER VAPOR SATELLITE IMAGERY WILL DRIVE
FIRST WEAK COLD FRONT INTO FORECAST AREA WEDNESDAY NIGHT. AHEAD OF
THE FRONT...PERSISTENCE LOOKS PRETTY GOOD FOR TEMPERATURES.
COVERAGE OF CONVECTION THAT DEVELOPS ALONG OR JUST BEHIND THIS
COLD FRONT ON WEDNESDAY IS QUESTIONABLE BECAUSE MID LEVEL
TEMPERATURES/THICKNESSES REMAIN PRETTY HIGH AND UPPER FORCING
WEAK. HOWEVER....TEMPERATURES AND THICKNESSES LOWER SLIGHTLY LATE
THURSDAY. ONE DIFFERENCE WILL BE HEATING AHEAD OF FRONT WILL BE
MORE PRONOUNCED WEDNESDAY WITH RESIDUAL CLOUDS/POSSIBLE SCATTERED
HIGH BASED SHOWERS/TSTMS LINGERING AND LIMITING HEATING SOMEWHAT
ON THURSDAY. NET NET WITH FORECAST WILL BE TO MAKE LITTLE/NO
CHANGES TO MODEST POPS WEDNESDAY NIGHT AND TO KEEP QPF ON LOWER
SIDE WEDNESDAY NIGHT/THURSDAY...WAY BELOW GFS. HIGH
THICKNESSES/MID LEVEL TEMPERATURES COULD BE A POSSIBLE HINDRANCE
IN COVERAGE DURING THAT TIME. HOWEVER...STARTED INCREASING POPS A
BIT THURSDAY AND EVEN MORE SO THURSDAY NIGHT WITH SLIGHTLY HIGHER
QPF AS MID LEVEL INHIBITION WEAKENS. PRECIPITABLE WATER WILL BE
HIGH AND STORMS PROBABLY EFFICIENT IN GENERATING HEAVY RAIN...BUT
WITH LITTLE UPPER SUPPORT DON/T KNOW IF WE CAN GENERATE A LARGE
MCS AND IT MAY BE MORE OF AN ALL OR NOTHING EVENT SIMILAR TO LAST
FRIDAY NIGHT. THUS SOME AREAS COULD RECEIVE IN EXCESS OF 1 OR 2
INCHES WHILE MANY OTHERS SEE LESS THAN A TENTH OF AN INCH OR EVEN
NOTHING. ALSO KEPT MOST MAX TEMPS IN UPPER 80S/LOWER 90S ON THU WITH
EXPECTED INCREASE IN CLOUDS.
A RECOVERY IN TEMPERATURES FRIDAY/SATURDAY AHEAD OF NEXT FRONT AND
HEAT HEADLINES COULD POSSIBLY HAVE TO BE READDRESSED...PERHAPS AS
EARLY AS FRIDAY IF DEW POINTS RECOVER A BIT FASTER THAN FORECAST.
LEFT IN SMALL POPS ON FRIDAY AS WARMER AIR RETURNS...BUT HAVE
DOUBTS. NEXT UPPER TROUGH SENDS NEXT WEAK FRONT THROUGH FORECAST
AREA SATURDAY NIGHT WITH GFS A LITTLE FARTHER SOUTH THAN 00Z ECMWF
AND EVEN MORE SO THAN WITH WAVE WEDNESDAY NIGHT. SO WITH
HEIGHTS/THICKNESSES LOWERING A BIT AND DECENT AGREEMENT IN QPF
PLACEMENT BETWEEN 12Z GFS AND 00Z ECMWF IN KEYING NEAR AND E OF MO
RIVER AFTER 06Z UPPED POPS A BIT N THRU E OF OMAHA.
UPPER RIDGE AND HEAT THEN TO RETURN NEXT WEEK...QUESTION ON HOW
LONG IT WILL LAST WILL BE ADDRESSED OVER NEXT FEW DAYS.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
VFR CONDITIONS WILL PREVAIL AT ALL THREE TAF SITES THROUGH THE
FORECAST PERIOD. HOT AND HUMID CONDITIONS WILL ALSO PREVAIL THROUGH
THE FORECAST PERIOD.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT WEDNESDAY FOR NEZ011-012-
015>018-030>034-042>045-050>053-065>068-078-088>093.
IA...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT WEDNESDAY FOR IAZ043-055-
056-069-079-080-090-091.
&&
$$
CHERMOK/MEYER