Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO

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FXUS63 KEAX 030940
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
440 AM CDT MON AUG 3 2015

.DISCUSSION...
Issued at 440 AM CDT MON AUG 3 2015

Today - Tonight:

Scattered convection continues to bubble within a narrow corridor
lying northwest-southeast over northwest MO. While a cold
front has nosed into northern MO it appears isentropic
ascent on the 305K and 310K surfaces is the primary
driver, the same mechanism which aided convection over the past 2
days. Due to several outflow boundaries put out by Sunday nights
convection its difficult to locate the cold front his morning.

The short range models weaken the isentropic ascent this morning so
the current convection should dissipate. Going forward think the
cold front will stall over the CWA today with model consensus
dividing the CWA in half. Isolated/widely scattered convection
possible along/north of the boundary during peak afternoon heating.
Pulse type convection with potential for microbursts due to extreme
instability, 0-6km shear of 4000J/kg near the front, and 25-
30kt of 0-6km shear.

Conditions for more organized/widespread convection expected
overnight due to a modest increase in the southwesterly low-level
jet. These winds should transport the higher theta-e air northeast
and over the slowly retreating front. Highest PoPs painted across
the northern 1/3 of the CWA.

Tuesday - Wednesday:

This looks like the most favorable period for more widespread
convection with heavy rain potential as precipitable water values
exceed 2 inches or around 150% of average or 99th percentile. Models
have been clear for the past 3 days that a well defined shortwave
trough will migrate eastward across the Central Rockies and Central
Plains. While there remains some timing and location differences
between the models they all agree that a couple rounds of convection
are likely over the CWA. High temperatures will be a bit problematic
as convective debris and any prolonged bouts of convection will
greatly limit heating. For now will shoot for the high end on the
assumption there will be sufficient heating to achieve seasonal
temperatures.

Thursday - Sunday:

Operational models gradually build the dome of high pressure back
into the central U.S. with surface riding from the Great Lakes
into the Mid MO Valley. This isn`t much different than previous
runs. What is different is the models now modify this airmass
over time resulting in slightly below average to average
temperatures.

Thursday night and Saturday night currently carry the highest
chances for rain which is typical for this time of year. Both
the GFS and ECMWF bring a couple shortwave troughs over the top of
the broad upper high and through IA/MO.

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday Night)
Issued at 1055 PM CDT SUN AUG 2 2015

Convection to the northeast will send a gust front over the KC area
around midnight. This will bring northeasterly winds, which could
gust up to around 20kts. At this point, convection along the boundary
is not likely during the overnight hours. Cloud cover will continue
to dissipate overnight as a cold front slowly works its way over the
area. Will see variable winds during the early morning hours before
transitioning to southeasterly by the afternoon hours. Additional
convection is possible overnight Monday, but should hold off through
the forecast period.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&

$$

DISCUSSION...MJ
AVIATION...Welsh


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