FXUS63 KOAX 302025
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
325 PM CDT SAT JUL 30 2011
.SHORT TERM...TONIGHT.
FOG WILL BE THE PRIMARY CONCERN OVERNIGHT AND THEN IF ANY CONVECTION
WILL GET CLOSE TO THE FORECAST AREA.
AT 19Z...A SURFACE FRONT EXTENDED FROM WESTERN NEBRASKA INTO SOUTH
DAKOTA AND MINNESOTA...WITH SURFACE HIGH PRESSURE OVER THE LOCAL
FORECAST AREA. THUNDERSTORMS WERE NOTED NEAR THE FRONT AROUND
WATERTOWN SOUTH DAKOTA AND THEN NEAR MINNEAPOLIS INTO WISCONSIN.
LOCALLY...SCATTERED CLOUDS SHOULD DIMINISH DIURNALLY WITH THE LOSS
OF HEATING. THE SURFACE HIGH PRESSURE RIDGE WILL STRETCH FROM
EASTERN NEBRASKA INTO IOWA. WITH LIGHT SURFACE FLOW AND LINGERING
LOW LEVEL MOISTURE/TRANSPIRATION FROM CROPS...WOULD EXPECT
CONDITIONS TO PROMOTE FOG DEVELOPMENT. REGARDING DENSE FOG...NOT
SURE HOW WIDESPREAD IT WILL BE. FORECAST SOUNDINGS SUPPORT
WIDESPREAD FOG...HOWEVER THERE IS DRIER AIR OFF THE SURFACE. IF
BOUNDARY LAYER WINDS REMAIN MORE MIXED...THERE WILL NOT BE AS MUCH
FOG. ADDED PATCHY/AREAS OF FOG STARTING LATE THIS EVENING AND SOME
DENSE FOG OVERNIGHT ESPECIALLY NEAR THE RIDGE AXIS AND IN LOW LYING
AREAS AND RIVER VALLEYS.
THE LOW LEVEL JET INCREASES OVER WESTERN NEBRASKA TONIGHT INTO SOUTH
DAKOTA WITH DEEP MOISTURE POOLING ALONG THE FRONT TO THE NORTH. THE
BETTER CHANCE FOR THE CONVECTION SHOULD BE ALONG THE FRONT. THE
PROPAGATION VECTORS ARE FROM NORTHWEST TO SOUTHEAST. THE 12Z 4KM
WRF DOES BRING THE CONVECTION INTO THE MISSOURI VALLEY AND THERE WAS
SUPPORT ON THE 00Z ECMWF...HOWEVER IT DOES NOT HAVE SUPPORT FROM THE
LATEST NAM/GFS/SREF/12Z ECMWF...THUS LEFT IT DRY IN THE NORTH.
.LONG TERM...SUNDAY THROUGH SATURDAY.
SOME FOG COULD LINGER INTO MID MORNING SUNDAY AND THEN PATCHY FOG IS
POSSIBLE AGAIN LATE SUNDAY NIGHT INTO EARLY MONDAY. OTHERWISE...
HEAT WILL BE THE MAIN ISSUE FROM SUNDAY INTO TUESDAY. DECIDED TO GO
AHEAD AND ISSUE A HEAT ADVISORY FOR ALL OF THE AREA STARTING EARLY
SUNDAY AFTERNOON. THEN WILL CONTINUE THAT UNTIL EARLY MONDAY EVENING
FOR ABOUT THE NORTHWEST HALF OF THE FORECAST AREA. THE ADVISORY FOR
THE SOUTHEAST HALF OF THE FORECAST AREA WILL CONTINUE UNTIL EARLY
TUESDAY EVENING. TIMING OF THIS IS BECAUSE OF FRONTAL LOCATION AS IT
PUSHES SOUTH/SOUTHEAST ACROSS THE AREA TUESDAY. PREFERRED A BLEND OF
THE 12Z NAM AND THE 12Z ECMWF IN REGARDS TO THE FRONT.
WATER VAPOR IMAGERY STILL SHOWED QUITE A BIT OF MONSOONAL MOISTURE
IN PLACE FROM MEXICO INTO THE CENTRAL ROCKIES. 12Z KOAX SOUNDING
SHOWED THE ATMOSPHERE HAD DRIED ABOVE 15,000 FEET. STILL EXPECT THAT
A MID TROPOSPHERIC RIDGE WILL BUILD OVER THE SOUTHERN AND CENTRAL
PLAINS FROM TONIGHT INTO MONDAY NIGHT. PATTERN RECOGNITION SUGGESTS
THAT MOST CONVECTION WILL OCCUR WEST AND NORTH OF OUR AREA DUE TO
THE WARM MID LEVEL TEMPERATURES. HOWEVER...A FEW MODERATELY STRONG
IMPULSES WERE MOVING NORTHWEST ACROSS PARTS OF NEW MEXICO AND
ARIZONA THIS AFTERNOON...AND WILL NEED TO BE MONITORED. 12Z RUN OF
THE GFS PRODUCED PRECIPITATION ACROSS OUR AREA MONDAY IN THE WARM
ADVECTION AREA AHEAD OF THE FRONT. AT THIS TIME...DID NOT GO WITH
THAT SOLUTION. WEAK COLD FRONT PUSHES THROUGH THE AREA TUESDAY AND
DID GO WITH SOME LOW THUNDERSTORM CHANCES BEHIND THE FRONT. MID
LEVEL TEMPERATURES REMAIN QUITE WARM THOUGH AND SHOULD LIMIT
COVERAGE. RAIN CHANCES LOOK BETTER FROM LATE WEDNESDAY NIGHT INTO
THURSDAY...AND HAVE PRECIPITATION CHANCES MORE IN THE 30-40 PERCENT
RANGE WITH RIDGE SUPPRESSED WELL TO THE SOUTH AT THAT TIME.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
MORNING FOG HAS LIFTED WITH SOME SCATTERED CLOUDS...WHICH SHOULD
GIVE WAY TO CLEAR SKIES DIURNALLY. THE SURFACE RIDGE OF HIGH
PRESSURE WILL REMAIN OVER THE AREA TONIGHT. AGAIN LIGHT WINDS...LOW
LEVEL MOISTURE AND A LARGER AREAL COVERAGE OF CLEARING SHOULD
PROMOTE WIDESPREAD FOG...WITH PATCHY DENSE FOG IN THE RIVER VALLEYS
AND IN THE SURFACE RIDGE AXIS. DID MENTION DENSE FOG AT THE TAF
SITES WITH IFR/LIFR VSBYS/CIGS BTWN 09-15Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY FROM NOON SUNDAY TO 7 PM CDT TUESDAY FOR NEZ045-
051>053-065>068-078-088>093.
HEAT ADVISORY FROM NOON SUNDAY TO 7 PM CDT MONDAY FOR NEZ011-012-
015>018-030>034-042>044-050.
IA...HEAT ADVISORY FROM NOON SUNDAY TO 7 PM CDT TUESDAY FOR IAZ055-
056-069-079-080-090-091.
HEAT ADVISORY FROM NOON SUNDAY TO 7 PM CDT MONDAY FOR IAZ043.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...MILLER