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000
FXUS63 KGID 181149
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
649 AM CDT SAT MAY 18 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 AM CDT SAT MAY 18 2013

AN INTERESTING DAY IS SHAPING UP ACROSS THE REGION AS THE LONGWAVE
TROUGH ACROSS THE INTERMOUNTAIN WEST IS EXPECTED TO SLOWLY
TRANSITION EASTWARD TOWARDS THE ROCKIES BY AFTERNOON. AHEAD OF THE
UPPER LEVEL TROUGH...A LEE TROUGH HAS DEVELOPED ACROSS THE HIGH
PLAINS AND IS AIDING IN MOISTURE TRANSPORT FROM THE SOUTH THIS
MORNING. AT THE SAME TIME...AN EXPANSIVE AREA OF LOW LEVEL STRATUS
IS SPREADING NORTHEASTWARD FROM WESTERN KANSAS...AS EVIDENT IN
SATELLITE IMAGERY...AND EXPECT AT LEAST THE POTENTIAL FOR CLOUDS TO
OVERTAKE THE ENTIRE FORECAST AREA BY DAYBREAK. WHILE SO FAR
OBSERVATIONS HAVE BEEN FREE OF PRECIPITATION WITH THIS
STRATUS...LATEST MODEL DATA CONTINUES TO HINT AT THE POTENTIAL FOR
SOME EMBEDDED LIGHT DRIZZLE...AND KEPT THIS POSSIBILITY IN THE
FORECAST THROUGH THE MID MORNING HOURS. ADDITIONALLY...WITH THIS
STRATUS INVADING THE REGION THIS MORNING...WENT AHEAD AND TWEAKED
DOWN AFTERNOON TEMPERATURES A FEW DEGREES TO COMPENSATE FOR A
SHORTER PERIOD OF DIURNAL HEATING...BUT STILL EXPECT THE STRATUS TO
EVENTUALLY CLEAR/MIX OUT BY LATE MORNING...ALLOWING INSTABILITY TO
BUILD ACROSS THE REGION.

FOCUS FOR AFTERNOON CONVECTION CONTINUES TO BE THE DRYLINE
POSITIONED TO THE WEST. WHILE INITIALLY...EXPECT THE STRATUS AND
WARM MID LEVELS WILL PUT A DAMPER ON ANY CONVECTIVE
DEVELOPMENT...THE CAP IS EXPECTED TO EVENTUALLY ERODE...ALLOWING FOR
EXPLOSIVE CONVECTION ALONG THE DRY LINE. THIS CONVECTION WILL THEN
BE ADVECTED EASTWARD DURING THE LATE AFTERNOON AND EARLY EVENING
HOURS. WITH PLENTY OF INSTABILITY TO WORK WITH...LARGE HAIL AND
STRONG WINDS WILL DEFINITELY BE A POSSIBILITY...WITH SHEAR
INCREASING AFTER 00Z...AND THE POSSIBILITY FOR TORNADIC STORMS...AS
THE LOW LEVEL JET STRENGTHENS AND BECOMES FOCUSED ACROSS CENTRAL AND
EASTERN NEBRASKA. WITH ALL THE FAVORABLE INGREDIENTS...FELT
CONFIDENT ENOUGH TO INCLUDED WORDING FOR SEVERE THUNDERSTORMS INTO
THE FORECAST THIS MORNING...FOR ROUGHLY THE 00Z-09Z PERIOD...WHERE
THE 00Z WRF IS FOCUSED AS WELL AS ABOUT THE TIME THE LATEST
RAP AND NAM BEGIN TO SPREAD CONVECTION OUR WAY. LATEST SPC
OUTLOOKS INDICATE A SLIGHT RISK FOR SEVERE STORMS TO AFFECT THE
ENTIRE FORECAST AREA...WITH A MODERATE RISK FOR SEVERE WEATHER
MAINLY WEST OF HIGHWAY 183.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 405 AM CDT SAT MAY 18 2013

BY 12Z SUNDAY...THE 500MB TROUGH WILL BEGIN TO SLIDE OVER THE
ROCKIES AND INTO THE GREAT PLAINS. AT THE SURFACE...ONE LOW IS
FORECAST TO SET UP OVER THE CWA...OR JUST SOUTH OF THE CWA...AND
ANOTHER SURFACE LOW IS FORECAST FOR EASTERN PARTS OF NORTH DAKOTA.
A COLD FRONT WILL EXTEND NORTHWARD THROUGH OUR CWA INTO THE
DAKOTAS...BASICALLY A LINE CONNECTING THE TWO LOWS. THIS COLD
FRONT WILL TRANSITION EASTWARD SUNDAY THROUGH BOTH NEBRASKA AND
KANSAS...WHICH WILL BE THE PRIMARY FOCUS OF THUNDERSTORMS. AHEAD
OF THE COLD FRONT WILL BE ADEQUATE MOISTURE...WHICH SHOULD RESULT
IN CAPE VALUES RANGING BETWEEN 1500 AND 2500 J/KG...ESPECIALLY
OUR EASTERN COUNTIES. THE NAM IS THE MOST AGGRESSIVE WITH REGARDS
TO 0-6 KM BULK SHEAR...INDICATING VALUES OF 50 KTS BY THE
AFTERNOON. THE GFS AND ECMWF STILL SUGGEST VALUES ROUGHLY BETWEEN
25 AND 35 KTS. AT 12Z...MODELS ARE ALSO SUGGESTING RELATIVELY
DECENT 0-1 KM SHEAR VALUES...MAINLY OUR EASTERN COUNTIES...BUT
QUICKLY DIMINISHES IN THE AFTERNOON. WITH ALL THIS BEING
SAID...THERE IS A GOOD CHANCE FOR SOME STRONG TO SEVERE
THUNDERSTORMS TO LINGER AROUND INTO SUNDAY ACROSS OUR
CWA...ESPECIALLY OUR COUNTIES EAST OF HIGHWAY 281. WOULD NOT BE
SURPRISED IF A FEW THUNDERSTORMS MET SEVERE CRITERIA ON SUNDAY
BEFORE DIMINISHING IN STRENGTH LATER IN THE DAY.

BEGINNING MONDAY...AND ESSENTIALLY THROUGH THE EXTENDED
PERIODS...THERE IS A MENTION OF SLIGHT CHANCE AND CHANCE POPS
THROUGH FRIDAY...WITH ONLY THE MENTION OF RAIN SHOWERS. THE LACK
OF INSTABILITY AND LIFT INDICATES THUNDERSTORMS ARE UNLIKELY AT
THIS TIME.

TEMPERATURES ON SUNDAY WILL BE ABOVE NORMAL. THEN TEMPERATURES WILL
COOL DOWN A LITTLE OVER THE WORKWEEK. IT APPEARS TUESDAY WILL BE THE
COLDEST DAY NEXT WEEK WITH MOST OF THE OUTLOOK AREA BELOW NORMAL.
OTHERWISE...TEMPERATURES NEXT WEEK WILL BE VERY CLOSE TO NORMAL.
NORMAL HIGHS ACROSS THE TRI-CITIES ARE IN THE LOWER 70S...WHILE LOWS
ARE USUALLY AROUND 50 DEGREES THIS TIME OF YEAR.

&&

.AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z SUNDAY MORNING)
ISSUED AT 645 AM CDT SAT MAY 18 2013

MVFR STRATUS...SOME -DZ AND BR HAVE ADVECTED ACROSS THE TERMINAL
THIS MORNING. EXPECT THIS STRATUS TO LIFT SOME AND FOR VFR
CONDITIONS TO RETURN AFT ABOUT 18/17Z...WITH A CHANCE FOR
THUNDERSTORMS...SOME OF WHICH COULD BE SEVERE...TO DEVELOP WEST OF
THE TERMINAL BY 19/00Z...AND THEN TRACK EAST ACROSS THE LOCAL
AREA DURING THE EVENING HOURS. WINDS WILL BE PRIMARILY
SOUTHEASTERLY AT 10 TO 20 KTS THROUGH THE PERIOD...WITH STRONGER
WIND GUSTS POSSIBLE WITH ANY STRONG OR SEVERE STORMS THAT DEVELOP
THIS EVENING.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

SHORT TERM...SAR
LONG TERM...GUERRERO
AVIATION...SAR