Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000
FXUS63 KOAX 280833
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
333 AM CDT SUN JUN 28 2015

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 332 AM CDT SUN JUN 28 2015

PRECIPITATION CHANCES THIS MORNING THEN AGAIN MONDAY NIGHT...WITH
WARM TEMPERATURES THE NEXT FEW DAYS...ARE THE PRIMARY FORECAST
CONCERNS.

NORTH-NORTHWEST UPPER FLOW PATTERN PERSISTS OVER THE NORTHERN INTO
THE CENTRAL PLAINS THIS MORNING. STRONG SHORTWAVE WAS NOTED ON
EVENING UPPER AIR MAPS AND LATEST WATER VAPOR IMAGERY DIVING INTO
NORTHERN MINNESOTA...WITH A 90KT 300MB JET KNIFING THROUGH THE
EASTERN DAKOTAS INTO WESTERN IOWA. AS EXPECTED...SCATTERED
CONVECTION FIRED IN MINNESOTA AND NORTHERN IOWA AHEAD OF
SHORTWAVE...WITH MORE ISOLATED ACTIVITY AS FAR WEST AS SOUTHEAST
SOUTH DAKOTA EARLIER THIS MORNING. SHORT-RANGE MESOSCALE MODEL
OUTPUT SUGGESTS SOME OF THIS ACTIVITY ON WESTERN FLANK OF PRECIP
AREA WILL SETTLE SOUTH THROUGH WESTERN IOWA...AND PERHAPS FAR
EASTERN NEBRASKA...THIS MORNING...WITH COVERAGE PRETTY ISOLATED WITH
WESTWARD EXTENT. WILL KEEP A MENTION OF THESE ISOLATED
SHOWERS/STORMS INTO MID MORNING BEFORE SHORTWAVE AND SURFACE WIND
SHIFT/FRONTAL REFLECTION SWEEPS SOUTH.

NORTH TO NORTHWEST WINDS WILL FOLLOW FRONT FOR THIS AFTERNOON...AND
COULD BECOME A BIT GUSTY AT TIMES. SHOULD SEE SIGNIFICANT DECREASE
IN CLOUD COVER WITH NEUTRAL TEMPERATURE ADVECTION AFTER MORNING COOL
PUSH. AND NEARLY UNIDIRECTIONAL FLOW THROUGH THE ATMOSPHERE WILL
PROMOTE DECENT MIXING. ALL OF WHICH POINT TO TEMPERATURES SIMILAR TO
SATURDAY HIGHS IN THE MID TO UPPER 80S.

PERSISTENCE WILL RULE THE FORECAST IN REGARDS TO TEMPERATURES
TONIGHT AND MONDAY WITH LOWS IN THE LOW TO MID 60S AND HIGHS IN THE
MID TO UPPER 80S. DECREASING WINDS AND CLOUDS ARE FORECAST
TONIGHT...WITH MOSTLY SUNNY SKIES AND LIGHT NORTH TO NORTHWEST WINDS
EXPECTED MONDAY.

A SIMILAR PATTERN TO SATURDAY EVENING/SUNDAY MORNING IS SETTING UP
FOR MONDAY NIGHT INTO TUESDAY MORNING. ANOTHER STRONG SHORTWAVE IS
ADVERTISED TO DROP INTO MINNESOTA AND IOWA MONDAY NIGHT...WITH
ANOTHER 90KT 300MB JET DIVING INTO THE PLAINS...THIS TIME NOSING
INTO EASTERN NEBRASKA. THUS WOULD EXPECT A SIMILAR RESULT REGARDING
SMALL PRECIP CHANCES. HOWEVER WILL NOT INTRODUCE A MENTION JUST YET
AS MODEL OUTPUT IS CONSISTENT AND EXPECTED COVERAGE SHOULD BE QUITE
ISOLATED. WILL INCREASE CLOUDS A BIT MONDAY NIGHT INTO TUESDAY
MORNING BEFORE WAVE/FRONT CLEARS OUR SOUTHERN FORECAST AREA.
CLEARING SKIES BUT AN EASTERLY LOW LEVEL WIND COMPONENT WILL PUT
HIGHS A COUPLE OF DEGREES COOLER TUESDAY AFTERNOON...BUT STILL IN
THE LOW TO MID 80S.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 332 AM CDT SUN JUN 28 2015

A MORE UNSETTLED NORTHWEST FLOW PATTERN IS SETTING UP FOR THE
TUESDAY NIGHT THROUGH SATURDAY PERIOD. SEVERAL IMPULSES ROLLING
SOUTHEAST INTO THE PLAINS WILL BRING OFF-AND-ON THUNDERSTORM
CHANCES...WITH VARIED MODEL OUTPUT SHOWING DIFFERENCES IN
TIMING...TRACKS AND AMPLITUDE WITH EACH FEATURE. THUS IT WILL BE
TOUGH TO PIN DOWN WITH ANY CONFIDENCE TIMES WHEN PRECIP CHANCES WILL
DROP BELOW SLIGHT CHANCE LEVELS...BUT WILL TRY TO HIGHLIGHT WITH
HIGHER POPS TIMES MORE SIGNIFICANT EPISODES ARE EXPECTED.

THAT FIRST EPISODE COMES EARLY IN THE PERIOD ON TUESDAY NIGHT INTO
WEDNESDAY AS STRONG ISENTROPIC UPGLIDE IS EXPECTED ON STRENGTHENING
LOW LEVEL JET WITH APPROACH OF FIRST SHORTWAVE. ECMWF HAS BEEN MORE
CONSISTENT WITH THIS FEATURE OVER THE PAST FEW DAYS AND WAS FOLLOWED
THIS FORECAST. EXPECT CONVECTION TO REALLY GET GOING AFTER
MIDNIGHT...AND SHOULD FAVOR THE NORTHEAST HALF OF EASTERN NEBRASKA
INTO WEST CENTRAL IOWA...ON COOL SIDE OF NORTHWEST TO SOUTHEAST
BAROCLINIC ZONE.

AFTER THIS CONVECTION TRACKS SOUTHEAST ON WEDNESDAY...A RELATIVE
LULL IN ACTIVITY IS LIKELY WEDNESDAY NIGHT WHEN ECMWF SUGGESTS
SHALLOW SHORTWAVE RIDGING BETWEEN EXITING IMPULSE AND NEXT ONE
SCHEDULED FOR THURSDAY AFTERNOON/NIGHT. ECMWF SHOWS A GENERAL
CYCLONIC FLOW PATTERN TO FOLLOW FRIDAY AS SHORTWAVE DRIFTS
SOUTHEAST...KEEPING PRECIP CHANCES GOING AT LEAST INTO FRIDAY NIGHT.

FOR NOW...THE FOURTH OF JULY SATURDAY LOOKS MAINLY DRY BEHIND THIS
EXITING SYSTEM...BUT EARLIER TIMING OF YET ANOTHER WAVE SCHEDULED TO
ARRIVE JUST PAST THIS FORECAST PERIOD WILL HAVE TO BE WATCHED.
OTHERWISE EXPECT GENERALLY SEASONABLE TEMPERATURES IN THE 80S
THROUGH THE PERIOD.

&&

.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1140 PM CDT SAT JUN 27 2015

STRONGER STORMS THAT WERE OVER SOUTH DAKOTA HAD WEAKENED...BUT
THE SHORTWAVE TROUGH DROPPING DOWN IN THE NORTHWEST FLOW COULD
TRIGGER SOME ISOLD TO SCT -SHRA/-TSRA OVERNIGHT. UNCERTAINTY
EXISTS ON COVERAGE BUT THINK KOFK AND KOMA COULD GET SOME LIGHT
PCPN. ANY CEILINGS WOULD LIKELY BE ABOVE 4000 FEET. WINDS WILL
SHIFT TO THE NORTHWEST AS A FRONT PASSES THROUGH...AND MAY BE A
BIT GUSTY BY SUNDAY AFTN.


&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

SHORT TERM...DERGAN
LONG TERM...DERGAN
AVIATION...MILLER



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