FXUS63 KOAX 150802
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
302 AM CDT WED JUN 15 2011
.DISCUSSION...
WE HAVE A SHORT BREAK IN THE WEATHER AS THE SHORT TERM CONCERNS
WILL BE TEMPERATURES TODAY...THEN IT IS BACK TO A STORMIER
WEATHER PATTERN WITH WARMER TEMPERATURES A CHANCE FOR SHOWERS AND
THUNDERSTORMS ON AND OFF LATE TONIGHT INTO NEXT WEEK.
THUNDERSTORMS HAVE QUICKLY SHIFTED EAST ACROSS IOWA WITH SURFACE
HIGH PRESSURE OVER THE AREA TODAY. SUNSHINE AND NORTHWEST WINDS
ALONG WITH DRIER DEWPOINTS SHOULD HELP TEMPERATURES TOP OUT IN THE
80S.
ALREADY THIS EVENING...THE NORTHWEST WINDS SWITCH AROUND TO THE
SOUTHEAST...AND THE LOW LEVEL JET OVER THE WESTERN PLAINS
STRENGTHENS TO 40KTS. THE MID TROPOSPHERIC TROUGH OVER NORTH
DAKOTA SHIFTS INTO WISCONSIN WEDNESDAY NIGHT...HOWEVER ANOTHER
LARGE CLOSED MID LEVEL LOW IS OVER SOUTHERN CANADA INTO MONTANA.
THE LOW LEVEL JET VEERS AND STRENGTHENS TO 50 KTS BY 12Z
THURSDAY. THE LOW LEVEL MOISTURE HAS NOT MADE IT BACK
YET...HOWEVER THERE IS ENOUGH MID LEVEL MOISTURE TO INCLUDE
MENTION OF ISOLATED OR SCATTERED THUNDERSTORMS. DURING THE DAY
WARM MID LEVEL TEMPERATURES BUILD BACK INTO THE PLAINS. AHEAD OF
THIS WARM NOSE AND A 50KT LOW LEVEL JET SHOULD MAINTAIN SOME
THUNDERSTORMS THURSDAY MORNING. CURRENT PROGS SHOW THAT BY
THURSDAY AFTERNOON...THERE IS A SURFACE BOUNDARY NEAR THE
NEBRASKA/KANSAS BORDER WITH VERY WARM MID LEVEL TEMPERATURES IN
PLACE AS A 40KT JET. OUTFLOW FROM THUNDERSTORMS EARLIER IN THE DAY
COULD AFFECT THE FRONTAL LOCATION. BY EVENING...STRONG INSTABILITY
MAY BE OVER CENTRAL AND EASTERN NEBRASKA INTO KANSAS WITH
K-INDICES GREATER THAN 40 FOR SOUTHEAST NEBRASKA INTO KANSAS. DEEP
LAYER SHEAR OF 40 TO 55KTS AND 0-1KM HELICITY IS PROGGED TO BE
AROUND 300 M2/S2 IN SOUTHEAST NEB. THESE PARAMETERS WOULD BE
SUPPORTIVE OF SUPERCELLS.
THURSDAY NIGHT...THE FORECAST WILL BE CONDITIONAL ON HOW STRONG THE
CAP IS...WHERE THE FRONTS ARE AND HOW STRONG THE FORCING IS. THE
THETA-E RIDGE IS IN PLACE OVER THE FORECAST AREA...WITH A 55KT JET
PROGGED OVER NORTHCENTRAL KANSAS. VERY STEEP 8.5 DEG C/KM LAPSE
RATES ARE ALSO PRESENT AND UPWARD VERTICAL MOTION WILL BE PRESENT
WITH SHORTWAVE TROUGH ENERGY ASSOCIATED IN THE SOUTHWEST FLOW
ALOFT. WITH THE ABOVE MENTIONED PARAMTERS...THERE IS THE POTENTIAL
FOR SEVERE WEATHER AND HEAVY RAIN.
THE WARM MID LEVEL TEMPERATURES REMAIN OVER THE MISSOURI RIVER
VALLEY FRIDAY AND FINALLY BREAKS DOWN MONDAY WHEN THE MID LEVEL TROF
MOVES INTO THE PLAINS. ALTHOUGH THESE WARM TEMPS WILL WORK TO HINDER
THE STORMS...IF THEY ARE ABLE TO BREAK THROUGH...STRONG TO SEVERE
STORMS WITH HEAVY RAIN WILL BE POSSIBLE. THIS WEATHER PATTERN WILL
MAKE TIMING OF THUNDERSTORMS AND TEMPERATURES A BIG CHALLENGE
THROUGH THE PERIOD. OVERALL TEMPERATURES LOOK TO BE AT OR ABOVE
NORMAL. WHEN THE MID LEVEL TROUGH MOVES THROUGH MONDAY INTO MONDAY
NIGHT...WE SHOULD SEE A GOOD CHANCE FOR STORMS. THE STORM SYSTEM
TAKES IT/S TIME MOVING OUT AS A SECONDARY TROUGH ROTATES AROUND THE
MID LEVEL LOW TUESDAY INTO WEDNESDAY.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE AREA FROM THE WEST.
LOW CLOUDS AND PATCHY MAY BE AROUND FOR A WHILE EARLY THIS MORNING
BUT VFR CONDITIONS SHOULD PREVAIL AFTER 12Z. NORTHWEST WINDS MAY
GUST TO AROUND 22-25 KNOTS AT TIMES FROM LATE MORNING THROUGH MID
AFTERNOON. THE HIGH PRESSURE SYSTEM WILL MOVE EAST OF THE AREA THIS
EVENING...WITH WINDS BECOMING SOUTHEAST AND MID LEVEL CLOUDINESS
INCREASING. THUNDERSTORMS POSSIBLE AFTER 06Z BUT CHANCES SEEM LOW
ENOUGH AT THIS TIME TO LEAVE OUT OF 12Z TAFS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY/MILLER