FXUS63 KGID 061705
AFDGID

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
1205 PM CDT MON OCT 6 2008

.AVIATION...RAIN AND ITS ASSOCIATED CEILINGS/VISIBILITIES WILL BE
THE MAIN ISSUES. WIDESPREAD RAIN EVENT CONTINUES TO IMPACT THE KGRI
TERMINAL LOCATION. EXPECT RAINFALL TO CONTINUE INTO THE EVENING
HOURS...WITH THE HEAVIEST RAINFALL DURING THE AFTERNOON. WILL CARRY
THE LOWEST CEILING/VISIBILITY RESTRICTIONS THROUGH THE
AFTERNOON...BUT TRY TO SHOW SOME IMPROVEMENT AS THE SYSTEM GRADUALLY
MOVES EAST THIS EVENING. DO NOT EXPECT VFR CONDITIONS TO RETURN
UNTIL AFTER 04Z. WINDS WILL ALSO BE DIFFICULT WITH EAST/SOUTHEAST
WINDS PREVAILING INITIALLY...BUT THEY SHOULD TURN TO THE
NORTH/NORTHWEST DURING THE MID AFTERNOON AS A FRONTAL BOUNDARY
CROSSES THE TERMINAL LOCATION.

&&

.PREV DISCUSSION... /ISSUED 249 AM CDT MON OCT 6 2008/

DISCUSSION...FOCUS IS THE UPCOMING RAIN EVENT TO UNFOLD TODAY
INTO TONIGHT. THE PATTERN ALOFT FEATURED AN ELONGATED TROUGH OF
LOW PRESSURE EXTENDING SOUTH FROM CANADA...THROUGH THE NORTHERN
ROCKIES AND SOUTHEAST INTO EASTERN COLORADO. AT THE SURFACE...LOW
PRESSURE CENTERS WERE LOCATED IN NORTH CENTRAL SOUTH DAKOTA AND IN
NORTHEAST NEW MEXICO. A COOL FRONTAL BOUNDARY EXTENDED SOUTH FROM
SOUTH DAKOTA INTO THE NEBRASKA PANHANDLE. THIS BOUNDARY SEPARATED
DRIER DPS IN THE 40S BEHIND THE FRONT FROM DPS IN THE MID 50S
AHEAD OF THE BOUNDARY. ISENTROPIC LIFT AHEAD OF THE SYSTEM HAS
PRODUCED SOME SCATTERED RAIN SHOWERS SO FAR TONIGHT. THE PCPN IS
EXPECTED TO FILL IN TODAY AS THE SOUTHERN EXTENT OF THE TROUGH
CLOSES AND LIFTS NORTHEAST INTO KS TODAY...RESULTING IN A
DEFORMATION BAND OF PCPN. FRONTOGENETIC FORCING ALSO INCREASES
WITH THE EASTWARD PROGRESSION OF THE COLD FRONT...WHICH IS EXPECTED
TO CROSS OUR CWA BETWEEN 18 AND 03Z. THE INCREASING
DYNAMICS/FORCING WILL RESULT IN WIDESPREAD RAINFALL FOR OUR
REGION...AND WITH PRECIPITABLE WATER VALUES AVERAGING AN INCH TO
AN INCH AND A HALF...OR 150 TO 200 PERCENT ABOVE NORMAL...THE
PROLONGED DURATION OF RAINFALL WILL LEAD TO SOME DECENT RAINFALL
TOTALS. WILL CONTINUE TO MENTION THE POTENTIAL FOR ONE TO TWO INCH
AMOUNTS IN THE HWO. GENERALLY SPEAKING WOULD NEED ABOUT DOUBLE
THIS AMOUNT OF RAINFALL TO CAUSE SIGNIFICANT HYDRO PROBLEMS. AS
FAR THE POTENTIAL FOR THUNDERSTORMS...MODELS INDICATE THE PRESENCE
OF SOME INSTABILITY AHEAD OF THE FRONTAL BOUNDARY AND HAVE
INCLUDED A MENTION OF ISOLATED THUNDER DURING THE DAY...BUT THIS
INSTABILITY RAPIDLY DIMINISHES BY EVENING.

MODELS HAVE TRENDED A LITTLE SLOWER WITH THE PROGRESSION OF THE
SYSTEM OVERALL. THE NAM HOLDS ONTO THE CLOSED LOW LONGER THAN THE
GFS...BUT GENERAL PRINCIPLE OF THE EVENT IS THE SAME. WITH THE
SLOWER TREND...HAVE LINGERED PCPN CHANCES LONGER INTO TUESDAY IN
OUR SE CWA. TEMPERATURES TODAY WILL ESSENTIALLY HAVE LITTLE
CHANGE FROM CURRENT READINGS IN THE LOW 60S WEST TO THE UPPER 60S
EAST.

HEIGHTS RISE ON TUESDAY BEHIND THE DEPARTING SYSTEM AND TEMPERATURES
SHOULD AVERAGE IN THE UPPER 60S TO NEAR 70F FOR HIGHS. MODEL
GUIDANCE SUGGESTS SOME LOW TEMPS IN THE MID/UPPER 30S TUESDAY NIGHT
IN THE DRIER AIRMASS IN OUR NORTHERN ZONES...WHICH ARE HOVERING CLOSE
TO FROST POTENTIAL. WILL NEED TO CONTINUE TO MONITOR...BUT THOUGHT
IS WITH THE WET GROUND FROM THE EXPECTED RAINFALL...LOW
TEMPERATURES WILL NOT BE QUITE THAT COOL AND HAVE TRENDED THE LOW
TEMPS HIGHER. ANOTHER BOUNDARY MOVES INTO OUR CWA WEDNESDAY WITH
LITTLE CONSEQUENCE AND TEMPS WILL BE FAIRLY SEASONAL.

&&

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

$$




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