000
FXUS63 KGID 231016
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
516 AM CDT THU MAY 23 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 515 AM CDT THU MAY 23 2013

THIS 24 HOURS MARKS THE VERY BEGINNING STAGES OF THE MORE
ACTIVE/STORMY WEATHER PATTERN THAT WILL RAMP UP HEADING INTO THE
HOLIDAY WEEKEND. LIKE LAST NIGHT...LOW LEVEL STRATUS TRENDS ARE
PRESENTING A CHALLENGE MAINLY DURING THE FIRST 6 HOURS. PRECIP-
WISE...HAVE INTRODUCED SPRINKLES INTO SOUTHWEST ZONES THIS
MORNING...AND OVERALL MADE LITTLE NOTABLE CHANGE TO OVERNIGHT
SHOWERS/STORM CHANCES...WHICH SHOULD NOT BE OVERLY WIDESPREAD.
ALSO MADE ONLY MINOR TWEAKS TO TEMPS TODAY/TONIGHT.

08Z OBJECTIVE CENTRAL PLAINS SURFACE ANALYSIS IS HIGHLIGHTED BY
THE SOUTHWARD EXTENSION OF A RATHER STRONG 1032+ MILLIBAR HIGH
CENTERED WELL TO THE NORTH OVER CENTRAL CANADA...WITH PRESSURES TO
AROUND 1018MB AS FAR SOUTH AS THE LOCAL CWA. THIS HIGH IS DRIVING
STEADY NORTH BREEZES GENERALLY 5-15 MPH EARLY THIS MORNING...WITH
LOCALLY HIGHER GUSTS. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM
MODEL DATA DEPICT THE DEPARTING MID LEVEL LOW THAT BROUGHT THE
LIGHT RAIN TO EASTERN AREAS 24 HOURS AGO NOW WELL OFF TO THE EAST
IN THE GREAT LAKES REGION...WHILE WELL UPSTREAM TO THE WEST AN
EXPANSIVE 500MB CLOSED LOW CONTINUES CHURNING OVER OR/WA. IN
BETWEEN THESE LOWS...A RIDGE AXIS EXTENDS NORTH-SOUTH THROUGH THE
HEART OF THE NATION...WITH ITS AXIS ALIGNED THROUGH WESTERN
PORTIONS OF NEB/KS. 11-3.9 MICRON SATELLITE IMAGERY CONFIRMS THAT
IN FACT THE STRATUS THAT ERODED NORTHWARD ACROSS MUCH OF THE CWA
ON WEDNESDAY HAS SUNK BACK SOUTHWARD OVERNIGHT...WITH THE MAJORITY
OF THE CWA SITTING UNDER A ROUGHLY 1500 FT CLOUD DECK. EARLIER IN
THE NIGHT...THERE WERE HINTS AT A FEW AUTOMATED STATIONS SUCH AS
ORD THAT BRIEF SPRINKLE/DRIZZLE MIGHT HAVE FALLEN...BUT OTHERWISE
THE CWA HAS REMAINED DRY THUS FAR...WITH OVERNIGHT LOW TEMPS
LIKELY ENDING UP BETWEEN 45-50 NEARLY ALL AREAS. LOOKING JUST TO
THE WEST...A CLASSIC NORTHWEST-SOUTHEAST BAND OF MID LEVEL THETA-E
ADVECTION EVIDENT ON BOTH THE 700MB AND 310K SURFACE IS DRIVING A
SURPRISINGLY HEALTHY AREA OF LIGHT RAIN SHOWERS OVER MAINLY
NORTHWEST KS/NORTHEAST CO...WITH A MORE ORGANIZED AREA OF
THUNDERSTORMS DEVELOPING ALONG THIS SAME ZONE OF LIFT MUCH FARTHER
SOUTH OVER OK.

HEADING INTO THE DAYTIME HOURS...THE MOST IMMEDIATE ISSUE IS TO
WHAT EXTENT THE LIGHT RAIN SHOWERS TO THE WEST WILL HOLD TOGETHER
AS THE MID LEVEL CORRIDOR OF LIFT CONTINUES EDGING EASTWARD TOWARD
THE CWA. GIVEN THAT THIS FORCING SHOULD CONTINUE WEAKENING A BIT
AS IT SPREADS EAST THIS MORNING...AND ALSO GIVEN A CONSIDERABLE
AMOUNT OF DRY AIR NOTED BELOW 600MB ON FORECAST SOUNDINGS...THINK
THE ODDS OF LEGITIMATE MEASURABLE RAIN AFFECTING MORE THAN A TINY
FRACTION OF THE WESTERN CWA THIS MORNING IS QUITE LOW. THAT BEING
SAID...WENT AHEAD AND INTRODUCED A SPRINKLE MENTION TO A
PREVIOUSLY RAIN-FREE FORECAST THROUGH MID-DAY FOR AREAS GENERALLY
SOUTHWEST OF A LEXINGTON-BELOIT LINE...WITH SEEMINGLY LITTLE RISK
FOR EVEN SPRINKLES FOR THE TRI-CITIES AND POINTS NORTH/EAST.
ALTHOUGH THIS SORT OF SETUP OFTEN PRODUCES AT LEAST A ROGUE
LIGHTNING STRIKE OR TWO...EVEN ELEVATED INSTABILITY IS ESSENTIALLY
NON-EXISTENT OVER THE CWA THIS MORNING SO WILL NOT GO THE
THUNDERSTORM ROUTE. AS FOR THE MID/UPPER LEVEL STORY TODAY...THE
AFOREMENTIONED RIDGE AXIS WILL AMPLIFY A BIT OVER THE CENTRAL
PLAINS TODAY...RESULTING IN RISING HEIGHTS. AT THE
SURFACE...WINDS WILL BE ON THE INCREASE A BIT AND TRANSITION FROM
NORTHERLY TO EASTERLY DUE TO THE COMBINATION OF HIGH PRESSURE TO
THE NORTH DRIFTING EAST...AND ALSO DECENT PRESSURE FALLS TO THE
WEST AS A FAIRLY STRONG SURFACE LOW RAMPS UP OVER WY. THIS
AFTERNOON...STEADY EASTERLY BREEZES AROUND 15 MPH WITH GUSTS INTO
THE 20-25 MPH RANGE WILL BE IN PLACE...STRONGEST WEST OF HIGHWAY
281. AS FOR THE EVOLUTION OF SKY COVER TODAY...WILL AGAIN LEAN
TOWARD THE LATEST RAP/HRRR LOW CLOUD/RELATIVE FIELDS...WHICH
SUGGESTS A FAIRLY RAPID SCATTERING OUT/LIFTING OF LOW CLOUDS
THROUGH THE MID-LATE MORNING HOURS...PAVING THE WAY FOR AN
AFTERNOON THAT SHOULD AVERAGE NO WORSE THAN PARTLY CLOUDY.
ASSUMING THIS ALL PANS OUT AS PLANNED...TEMPS SHOULD HAVE NO
PROBLEM MAKING A DECENT RISE...AND HAVE AIMED HIGHS BETWEEN 68-72
DEGREES FOR NEARLY THE ENTIRE CWA...WHICH IS ONLY SLIGHTLY WARMER
THAN PREVIOUS IN SOME SPOTS. AS FOR AFTERNOON PRECIP
CHANCES...KEPT IT DRY AS ANY CONVECTION SHOULD FOCUS AT LEAST A
FEW COUNTIES OFF TO THE SOUTH AND/OR WEST.

FOR THE TONIGHT PERIOD...00Z-12Z...LITTLE OVERALL CHANGE IN
THINKING FROM PREVIOUS FORECASTS. IN THE MID-UPPER LEVELS...FAIRLY
WEAK QUASI-ZONAL FLOW CONTINUES ACROSS THE CENTRAL PLAINS WITHIN
THE RIDGE AXIS...WHILE OFF TO THE WEST A LEAD SHORTWAVE TROUGH
EJECTS NORTHEAST ACROSS WY/MT ALONG THE SOUTHEAST SIDE OF THE
PARENT PACIFIC NORTHWEST LOW. AS THE NIGHT WEARS ON...ANOTHER MORE
VIGOROUS BATCH OF MID LEVEL THETA-E ADVECTION WILL VEER EASTWARD
ACROSS WESTERN/CENTRAL PORTIONS OF NEBRASKA/KANSAS. SLIGHTLY
LOWER IN THE COLUMN...A DECENT SOUTHERLY 850MB LOW LEVEL JET WILL
STRENGTHEN TO 30-45KT LATE IN THE NIGHT MAINLY ALONG THE FAR
WESTERN EDGE OF THE CWA AND POINTS WEST. NEEDLESS TO SAY...MODELS
VARY ON HOW MUCH QPF THEY GENERATE OVER THE CWA TONIGHT...WITH
SOME SUCH AS THE NAM AND EVEN 4KM WRF-NMM SHOWING LITTLE IF
ANYTHING GOING ON LOCALLY...WITH BETTER CHANCES FOCUSED WEST.
HOWEVER...GIVEN THE DECENT MID LEVEL THETA-E ADVECTION AND
FORECAST OF 200 + J/KG OF ELEVATED MUCAPE IN THE 850-700MB LAYER
FORECAST INTO PARTS OF THE CWA AFTER MIDNIGHT...AND HIGHER VALUES
TO AROUND 1000 J/KG IN THE FAR WESTERN COUNTIES...KEPT FAIRLY
MODEST 20-30 POPS GOING ESPECIALLY FOR THE 09Z-12Z TIME
FRAME...WHILE KEEPING THE ENTIRE EVENING TIME FRAME RAIN-FREE.
RELEGATED THESE STORM CHANCES WEST OF AN ORD-HASTINGS-BELOIT LINE
THROUGH SUNRISE...WITH CHANCES IN EASTERN COUNTIES HOLDING OFF
UNTIL THE FRIDAY DAYTIME PERIOD. ALTHOUGH NOT EXPECTING ANY SEVERE
STORMS LATE TONIGHT...CERTAINLY CANNOT RULE OUT SOME SMALL HAIL
ESPECIALLY IN THE FAR WESTERN FRINGES OF THE CWA. COULD ALSO SEE
RENEWED LOW STRATUS DEVELOPMENT AS LOW LEVEL WINDS TURN MORE
SOUTHEASTERLY. SURFACE BREEZES OF 10-15 MPH WILL PREVAIL THROUGH
THE NIGHT...AND MADE ONLY MINOR CHANGES TO LOW TEMPS WITH MOST
AREAS BOTTOMING OUT WITHIN A FEW DEGREES EITHER SIDE OF 50.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 515 AM CDT THU MAY 23 2013

THE WEATHER PATTERN WILL BECOME MORE ACTIVE IN THESE EXTENDED PERIODS.
ON FRIDAY...AN UPPER LEVEL RIDGE AXIS WILL BE IN PLACE ACROSS THE
CENTRAL PLAINS IN BETWEEN AN UPPER LOW IN THE PACIFIC NORTHWEST AND
AN UPPER LOW/TROUGH ALONG THE EASTERN CONUS.  A WARM FRONTAL
BOUNDARY LIFTS E/NE ACROSS THE CENTRAL PLAINS DURING THE DAY AND IN
WAA/THETA E ADVECTION...SHOWERS AND TSTMS ARE EXPECTED TO DEVELOP
AND SPREAD EAST/NORTHEAST FRIDAY/FRIDAY NIGHT.  DUE TO ANTICIPATED
PCPN AND CLOUD COVER ON FRIDAY...HAVE LOWERED HIGH TEMPS A FEW
DEGREES.  INSTABILITY PARAMETERS INDICATE CAPES INCREASING TO 1000
J/KG WITH SOME HIGHER INSTABILITY POTENTIAL GREATER THAN THIS
POSSIBLE ACROSS OUR WESTERN ZONES...AND EFFECTIVE SHEAR IS PROGGED
AROUND 30KTS.  COULD SEE A FEW STRONG/SEVERE STORMS BY FRIDAY
AFTN/EVE AND MORE SO INTO FRIDAY NIGHT...AS LLVL JET INCREASES.
MODELS SUGGEST ADDITIONAL CONVECTIVE POTENTIAL ALONG HIGH PLAINS
FRIDAY NIGHT IN VCNTY OF SFC LOW/DRY LINE WHICH MAY THEN ROLL ACROSS
OUR REGION OVERNIGHT.

ON SATURDAY...FLOW ALOFT WILL BE SOUTHWESTERLY AS RIDGE AXIS SHIFTS
EASTWARD...WHILE AT THE SFC...LOW PRESSURE SHOULD SETTLE ALONG THE
HIGH PLAINS WITH TWO POTENTIAL SFC LOW CENTERS DEVELOPING...ONE IN
EASTERN WY/MT AND ANOTHER TO THE SOUTH ACROSS WESTERN KS.  WARM
FRONTAL BOUNDARY LOOKS TO SETTLE NEAR THE NEB/KS START LINE WITH MUCH
GREATER INSTABILITY EXPECTED WITH CAPES IN EXCESS OF 3000 J/KG AS
MOISTURE POOLS ALONG THE BOUNDARY...AND AGAIN DECENT SHEAR IS
PROGGED AROUND 30KTS...ESPECIALLY ACROSS NEB WHICH INCREASES
OVERNIGHT WITH NOCTURNAL JET.  WARM MID LEVEL TEMPS COULD MAY INHIBIT
CONVECTION TO THE WEST ALONG THE DRY LINE...HOWEVER WARM FRONT LOOKS
TO BECOME ACTIVE AND IF STORMS FIRE IN VCNTY OF FRONT...CONDITIONS
ARE FAVORABLE FOR SEVERE WEATHER.  CONVECTIVE POTENTIAL CONTINUES
INTO SATURDAY NIGHT MAINLY ACROSS NEB NORTH OF FRONT ON NOSE OF 50KT
LLVL JET.

THROUGH THE REMAINDER OF THE MEMORIAL DAY HOLIDAY
WEEKEND...SUNDAY/MONDAY...CONVECTIVE POTENTIAL CONTINUES IN
SOUTHWEST FLOW ALOFT AS SHORTWAVE ENERGY LIFTS ACROSS THE PLAINS AND
INTERACTS WITH LLVL BOUNDARIES.  TIMING/LOCATION OF BEST PCPN CHCS
WILL BE REFINED WITH TIME.  THIS BEING SAID...THE WEATHER PATTERN
DOES LOOK ACTIVE WITH POTENTIAL FOR SEVERE WEATHER AND DECENT
RAINFALL/PCPN IS POSSIBLE FOR SEVERAL DAYS IN INCREASED
MOISTURE...AND PRECIPITABLE WATER VALUES INCREASE TO BETWEEN AN INCH
AND AN INCH AND A HALF.

BY MID WEEK...EXTENDED MODELS BEGIN TO DIVERGE IN HANDLING OF
TROUGH/UPPER LOW ACROSS THE WESTERN CONUS AND DUE TO MODEL
DIFFERENCES...DID NOT DEVIATE MUCH FROM EXTENDED INIT.

&&

.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1252 AM CDT THU MAY 23 2013

AS WAS THE CASE 24 HOURS AGO...CEILING TRENDS VARYING BETWEEN MVFR
AND VFR CONTINUE TO BE THE BIGGEST...TRICKY CHALLENGE...ESPECIALLY
THROUGH THE FIRST 12 HOURS OF THE PERIOD. HOWEVER...CONFIDENCE
REMAINS RATHER HIGH IN VFR VISIBILITY...AND ALSO THAT IT SHOULD
REMAIN RAIN-FREE THROUGH THE PERIOD. GETTING BACK TO CEILINGS...A
FAIRLY SOLID DECK OF STRATUS RANGING ANYWHERE FROM 1500 TO AROUND
3000 FT CONTINUES SINKING SOUTHWARD ACROSS SOUTHERN NEBRASKA.
ALTHOUGH KGRI COULD VERY WELL BOUNCE BACK AND FORTH BETWEEN VFR
AND MVFR THROUGH MUCH OF THE NIGHT...WILL AIM FOR PREVAILING MVFR
FOR SEVERAL HOURS AND LIKELY LASTING THROUGH SOMETIME AROUND MID-
DAY BEFORE LOW STRATUS IS EXPECTED TO EITHER START SCATTERING OUT
AND/OR LIFTING INTO LOW-END VFR LEVELS...AND REMAINING THAT WAY
THROUGH THE END OF THE PERIOD. AS FOR SURFACE WINDS...A FAIRLY
LIGHT NORTHERLY BREEZE WILL PREVAIL EARLY THIS MORNING...BEFORE
STEADILY TURNING MORE EASTERLY BY MID-DAY WITH GUST POTENTIAL TO
AT LEAST 18KT FOR MUCH OF THE AFTERNOON. WINDS WILL REMAIN
EASTERLY THURSDAY EVENING SUSTAINED ROUGHLY 10KT.


&&

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

$$

SHORT TERM...PFANNKUCH
LONG TERM...FAY
AVIATION...PFANNKUCH