Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KOAX 221219
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
719 AM CDT FRI AUG 22 2014

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 341 AM CDT FRI AUG 22 2014

CONVECTIVE ACTIVITY HAS DEVELOPED OVER SWRN IA AND SERN NEB THIS
MORNING ALONG A SFC TROF EXTENDING FROM NRN IA TO WRN KS. SIMILAR
TO THE LAST SEVERAL NIGHTS...ENVIRONMENT IS QUITE UNSTABLE WITH
MUCAPES AROUND 3000 J/KG WITH A STRONG LLVL MOISTURE FEED INTO THE
PLAINS. EXPECT ACTIVITY WILL GRADUALLY DIMINISH OVER THE NEXT
SEVERAL HOURS AND BE OUT OF THE CWA BY SUNRISE.

MOST PRESSING ISSUE FOR THIS FCST PACKAGE IS POTENTIAL SVR
TSTMS ALONG WITH HEFTY RAINFALL ANTICIPATED LATER TONIGHT.

MODELS HAVE BEEN CONSISTENT LAST SEVERAL RUNS FOCUSING IN ON THE
NRN CWA WITH RESPECT TO HIGH POTENTIAL FOR HEAVY NOCTURNAL PCPN
LATER TONIGHT. AN OPEN GULF WITH PERSISTENT MOISTURE ADV THRU
TODAY WILL ENSURE A MOISTURE RICH ENVIRONMENT WILL BE IN PLACE
DURING THE OVERNIGHT HOURS.

TODAY...MODELS PROG A POTENT LITTLE VORT MAX EJECTING OUT OF THE
BASE OF A DEEP UPPER TROF SITUATED OVER THE WRN CONUS WITH DPVA
INDUCING LEESIDE CYCLOGENESIS INVOF THE CNTRL HIGH PLAINS. MODELS
AGREE SFC LOW WILL RAPIDLY LIFT TWD THE DAKOTAS THIS AFTN ALONG
WITH ATTENDANT WARM FRONT PUSHING INTO THE CWA LATE THIS AFTN.
COMBINATION OF STOUT INSTABILITY/EFF SHEAR AND ADEQUATE DEEP LYR
SHEAR WITH PROVIDE A FAVORABLE ENVIRONMENT FOR LATE AFTN/EARLY
EVENING SUPERCELL DEVELOPMENT. IN ADDITION...VERY HEAVY
RAINFALL...MAINLY OVER THE NRN CWA...LOOKS VERY PROBABLE TONIGHT
GIVEN COMBINATION OF WARM CLOUD DEPTH AROUND 4500 METERS/SYNOPTIC
SCALE MAX OMEGA WILL BE IN PHASE WITH PWS GREATER THAN 2". BEST
MOISTURE/FORCING THEN QUICKLY LIFTS NORTH OF THE CWA EARLY SAT
MORNING.

SAT NIGHT AND SUN...MODELS PROG A SOMEWHAT STRONG COLD FRONT
APPROACHING THE CWA. NOT ALL THAT IMPRESSED WITH PCPN POTENTIAL SO
WILL OPT FOR TOKEN 20S DURING THOSE PDS.

.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 341 AM CDT FRI AUG 22 2014

COMPARED TO 21/00Z RUN...LATEST ECM IS NOW TRYING TO COME BACK IN
LINE WITH GFS/CMC SOLUTIONS SWEEPING A CANADIAN AIR MASS INTO THE
NRN/CNTRL PLAINS LATER NEXT WEEK WITH PCPN CHANCES FOCUSED ON
FRONTAL BNDRY PASSAGE. GOING POPS LOOK REASONABLE THUS NO MAJOR
CHANGES PLANNED.

&&

.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 658 AM CDT FRI AUG 22 2014

THERE MAY BE SOME PATCHY FOG EARLY THIS MORNING WITH HIGH SURFACE
DEWPOINTS AND LIGHT AND VARIABLE WINDS...SO INCLUDED A COUPLE OF
HOURS OF MVFR CIGS. DIFFICULT FORECAST TODAY AS THERE ARE A COUPLE
OF BOUNDARIES IN THE AREA AND A HIGH DEGREE OF MOISTURE. DO NOT
MENTION TSRA AS EXPECT THE LOW LEVEL JET TO WEAKEN AND BETTER
FORCING IS TO THE SOUTH OF THE TAF SITES. SHORTWAVE TROF ENERGY
WILL MOVE INTO THE PLAINS LATER TONIGHT AND TONIGHT. THE FORECAST
SOUNDINGS SHOW THE CAP WEAKENING TOWARD 00Z WITH ELEVATED
INSTABILITY PRIOR 00Z AND MODERATE TO STRONG INSTABILITY AT 00Z.
TIMING OF TSRA WAS MENTIONED LATE THIS AFTERNOON AND TONIGHT.
WILL NEED TO BE MONITOR AS STORMS BEGIN TO ORGANIZE. SOME STORMS
MAY BE SEVERE AND PRODUCE IFR/LIFR VSBYS/CIGS...HOWEVER DUE TO
UNCERTAINTY OF TIMING AND LOCATION OF THE STRONGER STORMS WILL
MENTION MVFR VSBYS FOR NOW.

&&

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

$$

SHORT TERM...DEE
LONG TERM...DEE
AVIATION...ZAPOTOCNY



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.