FXUS63 KGID 211154

AFDGID



AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE HASTINGS NE

654 AM CDT TUE APR 21 2015



.UPDATE...

ISSUED AT 654 AM CDT TUE APR 21 2015



IR SATELLITE SHOWS OVERNIGHT ALTOCU HAS DIMINISHED AND MOVED SE

...BUT ANOTHER LARGE AREA IS HEADING SE THRU SD. TIMING TOOL

BRINGS IT INTO OUR NRN COUNTIES BY 15Z. SO SKY COVER WAS INCREASED

WITH THIS UPDATE.



A COUPLE OTHER NOTES. THE 06Z NAM CAME IN MORE ROBUST WITH

POTENTIAL FOR A FEW SPRINKLES WITH THIS EVENING'S FRONTAL PASSAGE.

CLOUD DEPTH/INSTABILITY IS GREATER AND WOULD SUPPORT PRECIP

GENERATION. SPRINKLES MAY NEED TO BE ADDED TO THE FCST. 



WATCH THE NE WINDS WITH THE FRONTAL PASSAGE THIS EVE. THE 06Z NAM

ALSO SHOWS A TIGHT PRES GRAD IMMEDIATELY BEHIND THE FRONT. THE

FCST MAY NEED TO BETTER REFLECT A PERIOD OF BRIEF GUSTY NE WINDS.



&&



.SHORT TERM...(TODAY AND TONIGHT)

ISSUED AT 403 AM CDT TUE APR 21 2015



ALOFT: NW FLOW THRU TONIGHT WITH AN ANOMALOUSLY DEEP LOW SLOWLY

LIFTING FROM THE GREAT LAKES INTO ONTARIO...AND A W COAST RIDGE

THAT MAKES SLOW BUT STEADY PROGRESS INTO THE INTERMOUNTAIN W. WV

IMAGERY SHOWS A VERY SUBTLE SHORTWAVE TROF DIVING S OUT OF

SASKATCHEWAN INTO THE DAKOTAS. THIS TROF WILL CONT AROUND THE

BACKSIDE OF THE GREAT LAKES LOW AND HEAD INTO THE MIDWEST TONIGHT.

THE NEXT SHOT OF COOL AIR WILL BE DELIVERED BY THIS TROF.



SURFACE: A WEAK/SUBTLE LOW WAS OVER MT. THIS LOW WILL MOVE SSE

AND ACROSS NEB TODAY ALONG WITH ITS TRAILING COOL FRONT. FRONTAL

PASSAGE WILL THIS AFTERNOON-EVE. A PIECE OF CNTRL CANADA HIGH PRES

WILL BREAK OFF DROP S AND SETTLE OVER THE REGION TONIGHT.



TODAY: OVERALL P/CLOUDY AND BREEZY WITH PATCHES OF MID-LVL ALTOCU

DRIFTING THRU AND/OR DEVELOPING WITH DAYTIME HEATING. HIGHS WILL

BE A LITTLE WARMER THAN NORMAL.



SUSTAINED WINDS AND GUSTS WERE INCREASED ABOVE MOS WITH DEEP

MIXING. ALSO USED THE MIX-DOWN TOOL TO LOWER DWPTS THIS AFTERNOON.



TONIGHT: DIURNAL ALTOCU DISSIPATE LEAVING CLEAR SKIES. GOOD

RADIATING. THE USUAL COLD SPOTS IN THE N LOUP RIVER VALLEY WILL

DROP INTO THE MID 20S...AND POSSIBLY INTO THE LWR 20S.





.LONG TERM...(WEDNESDAY THROUGH MONDAY)

ISSUED AT 403 AM CDT TUE APR 21 2015



THE UPPER LEVEL LOW PRESSURE SYSTEM OVER SOUTHERN CALIFORNIA AND

VISIBLE IN WATER VAPOR IMAGERY THIS MORNING WILL BECOME THE FOCUS

FOR SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE LOCAL AREA

BEGINNING THURSDAY...WITH UNSETTLED WEATHER FORECAST TO CONTINUE

FOR SEVERAL DAYS BEFORE A RIDGE OF HIGH PRESSURE BUILDS ACROSS THE

INTERMOUNTAIN WEST EARLY NEXT WEEK...EVENTUALLY BRINGING WARMER

AND DRIER AIR TO THE REGION. WITH PLENTY OF DIVERGENCE IN LONG

TERM MODELS...UNCERTAINTY IN TIMING AND OVERALL RAINFALL CHANCES

IS FAIRLY HIGH...BUT MOST AREAS SHOULD AT LEAST SEE SOME SHOWER

ACTIVITY LATER THIS WEEK.



WHILE WEDNESDAY IS EXPECTED TO START OFF ON THE COOL SIDE AS AN

AREA OF SURFACE HIGH PRESSURE WILL BE CENTERED ACROSS THE LOCAL

AREA...EXPECT SOUTHERLY FLOW ON THE BACKSIDE OF THIS SYSTEM TO

BEGIN TO ADVECT MOISTURE NORTHWARD LATE IN THE DAY AS THIS HIGH

SHIFTS TO THE SOUTHEAST. THAT SAID...WITH FAIRLY LIGHT WINDS

FORECAST...EVEN BELOW NORMAL TEMPERATURES WEDNESDAY AFTERNOON

SHOULD FEEL FAIRLY NICE.



AS THE MOISTURE POOL DEEPENS ACROSS THE LOCAL AREA LATE

WEDNESDAY/THURSDAY...EXPECT THE AFOREMENTIONED UPPER LEVEL LOW TO

BEGIN TO SPREAD ITS INFLUENCE ACROSS THE LOCAL AREA BY

THURSDAY...RESULTING IN INCREASING CHANCES FOR SHOWER ACTIVITY

ACROSS THE LOCAL AREA. WHILE THE INSTABILITY IS FAIRLY LOW...ON

THE ORDER OF ONLY A COUPLE HUNDRED JOULES OF CAPE AND MAINLY

LIMITED SOUTH OF INTERSTATE 80...COULD SEE SOME ISOLATED

THUNDERSTORMS DEVELOP AS WELL...BUT SEVERE STORMS ARE NOT

ANTICIPATED GIVEN THE UNDERLYING AIRMASS. OTHERWISE...CLOUDY AND

OCCASIONALLY SHOWERY CONDITIONS CAN BE EXPECTED FOR FRIDAY AS

MODELS ARE IN FAIR AGREEMENT TRACKING THIS UPPER LEVEL LOW ACROSS

KANSAS FRIDAY AFTERNOON/EVENING.



THEREAFTER...THE FLOW WILL REMAIN A BIT MESSY AS YET ANOTHER

DISTURBANCE IN THE SOUTHERN BRANCH OF THE JET STREAM MAY IMPACT

THE LOCAL AREA LATER IN THE WEEKEND BEFORE HIGH PRESSURE

EVENTUALLY BUILDS ACROSS THE INTERMOUNTAIN WEST. GIVEN THE

UNCERTAINTY IN THIS SOLUTION...DID NOT ALTER BLENDED MODEL

SOLUTIONS SIGNIFICANTLY AND KEPT THUNDERSTORMS OUT OF THE FORECAST

AS INSTABILITY IS VERY MINIMAL. DEPENDING ON HOW FAR EAST THE

UPPER LEVEL RIDGE ADVANCES EARLY NEXT WEEK WILL HAVE A SIGNIFICANT

IMPACT ON TEMPS...WITH THE EC NOT NEARLY AS AGGRESSIVE TAKING THIS

RIDGE INTO THE PLAINS...BUT PRESENTLY HAVE LOWER TO MIDDLE 70S

FORECAST TO START THE NEW WORK WEEK PER MODEL BLENDS...WHICH WOULD

BE ABOUT 5-10 DEGREES ABOVE SEASONAL NORMS FOR LATE APRIL. THAT

SAID...THE EC IS MUCH COOLER...KEEPING AFTERNOON TEMPERATURES NEAR

OR BELOW CLIMO FOR THE NEXT 7 DAYS.



&&



.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z WED MORNING)

ISSUED AT 654 AM CDT TUE APR 21 2015



TODAY: VFR WITH SCT TO OCCASIONALLY BKN CIGS 9-11K FT. NW WINDS

INCREASE 15Z-16Z AND COULD GUST AS HIGH AS 30 KTS. CONFIDENCE:

HIGH



TUE EVE: VFR CLEARING. COOL FRONTAL PASSAGE 00Z-01Z. WSHFT TO NE

AND WINDS COULD GUST UP TO 25 KTS BRIEFLY. WIND THEN DIMINISH TO

UNDER 10 KTS. CONFIDENCE: HIGH



&&



.GID WATCHES/WARNINGS/ADVISORIES...

NE...NONE.

KS...NONE.

&&



$$



UPDATE...HALBLAUB

SHORT TERM...HALBLAUB

LONG TERM...ROSSI

AVIATION...HALBLAUB