FXUS63 KOAX 040831
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
331 AM CDT MON JUL 4 2011
.DISCUSSION...
SHORT TERM CONCERNS FOR TODAY ARE IN REGARDS TO AREAS OF FOG AND
STRATUS THIS MORNING...THEN HIGHS THIS AFTERNOON. LARGE SCALE
PATTERN SHOWS A MID TROPOSPHERIC RIDGE CENTERED OVER THE FOUR
CORNERS REGION WITH MONSOONAL MOISTURE FEEDING NORTH FROM WESTERN
MEXICO INTO ARIZONA...NEVADA AND UTAH. FAIRLY FAST FLOW EXTENDED
FROM THE PACIFIC NORTHWEST INTO SOUTH CENTRAL CANADA AND INTO
NORTH DAKOTA. A FAIRLY IMPRESSIVE WAVE WAS NOTED. FOR TODAY...
MODELS SUGGEST THAT THE MID LEVEL RIDGE WILL EXPAND SLIGHTLY
EASTWARD INTO THE WESTERN PARTS OF NEBRASKA AND KANSAS.
SATELLITE IMAGERY EARLY THIS MORNING SHOWED STRATUS INCREASING OVER
PARTS OF CENTRAL AND EASTERN NEBRASKA. VISIBILITIES SO FAR HAVE BEEN
MOSTLY GREATER THAN 3 MILES...BUT WILL PROBABLY GO LOWER TOWARD
SUNRISE. LOW LEVEL RELATIVE HUMIDITY FORECASTS SUGGEST SCATTERED TO
BROKEN LOW CLOUDS HANGING AROUND FOR THIS MORNING. EXPECT MOSTLY
SUNNY SKIES THIS AFTERNOON WITH HIGHS MAINLY 85 TO 90. 700 MB
TEMPERATURES SHOULD BE WARMING DURING THE DAY WITH A MODEST CAP BY
LATE AFTERNOON. THIS CAP SHOULD REMAIN IN PLACE AT LEAST THE FIRST
HALF OF TONIGHT. AS A COLD FRONT APPROACHES FROM THE NORTHWEST LATE
TONIGHT AND TUESDAY MORNING...THE CAP SHOULD WEAKEN ACROSS NORTHEAST
NEBRASKA. KEPT THUNDERSTORM CHANCES MAINLY 20 TO 30 PERCENT THERE
TONIGHT...BUT SPREAD CHANCES SOUTHEAST ACROSS ALL OF THE AREA ON
TUESDAY AS HEIGHTS DECREASE SLIGHTLY. GENERALLY USED A BLEND OF THE
00Z NAM...00Z GFS AND 00Z ECMWF TUESDAY.
WE REMAIN GENERALLY ON THE SOUTHERN EDGE OF STRONGER WEST/NORTHWEST
MID LEVEL FLOW WEDNESDAY THROUGH FRIDAY AS 500 MB RIDGE REMAINS IN
PLACE ACROSS THE FOUR CORNERS REGION. THIS RIDGE MOVES INTO TEXAS...
OKLAHOMA AND SOUTHERN KANSAS BY SATURDAY. ALTHOUGH THE MODELS WERE
IN FAIRLY GOOD AGREEMENT WITH THE OVERALL PATTERN...THEY DO NOT
AGREE ON THE FINER SCALE DETAILS IN REGARDS TO THE DEVELOPMENT OF
THUNDERSTORMS. SO CONFIDENCE ON TIMING RAIN CHANCES IN THE MID AND
LATER PART OF THE WEEK IS AT OR BELOW AVERAGE. BOTH THE 00Z ECMWF
AND THE 00Z GFS SHOW THE CENTER OF 500 MB RIDGE MOVING TO MISSOURI
AND ILLINOIS BY MONDAY. THIS SHOULD PUSH HIGHS INTO THE LOWER AND
MID 90S FOR THE SOUTHERN PARTS OF THE FORECAST AREA...WITH MID 80S
TO AROUND 90 NORTH.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
SURFACE HIGH PRESSURE OVER IOWA WILL REMAIN OVER THE AREA THEN SHIFT
INTO ILLINOIS DURING THE PERIOD. EARLY ON PATCHY LOW CLOUDS AND FOG
WILL BE THE FORECAST CONCERNS AS SURFACE DEWPOINT DEPRESSIONS
DECREASE WITH LIGHT WINDS AND CLEAR SKIES. HAVE MVFR/IFR VSBYS THRU
AROUND 14Z. A PATCH OF LIFR CONDITIONS HAVE DEVELOPED AT KBVN AND
KAUH. IN THE TAF WILL NEED TO WATCH AS HAVE MVFR/IFR CIGS POSSIBLE
AT KOFK AND KLNK FOR A FEW HOURS THIS MORNING. FORECAST SOUNDINGS
SHOW THAT WITH THE HEATING TODAY...SHOULD SEE SOME CUMULUS CLOUDS
AROUND 3K FEET.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
DISCUSSION...MILLER
AVIATION...ZAPOTOCNY