857 FXUS63 KEAX 051744 AFDEAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 1244 PM CDT WED AUG 5 2015 .DISCUSSION... Issued at 429 AM CDT WED AUG 5 2015 It's another night watching storms percolate across the Plains States with the potential for storms to linger on through much of the day. Looking at he big picture across the Nation early this morning, water vapor imagery shows a moderately amplified flow across the contiguous U.S.A. with a ridge axis along the front range of the Rocky's. Within the larger pattern are noted a number of shortwave troughs that will influence our weather over the next 48 hours. first shortwave to note is seen spinning its way into eastern Kansas early this morning thanks to the northwest flow. Second shortwave of note is cresting the ridge axis along the Dakota border with Canada. Today... The shortwave in eastern Kansas has already generated some extensive convection across Kansas early this morning, and with the help of a 25 knot southwest nocturnal jet --as sampled off the radar wind profilers-- more storms are bubbling up across southeast Kansas into southwest Missouri this morning. Farther east, across central Missouri, isentropic lift ahead of the shortwave on the 305K surface has developed showers. Expect this activity in both areas to fill in through the morning hours as the shortwave continues to dig to the southeast. This does not change the going forecast much, though the ultimate expectations have been adjusted. Still looks like much of the region will likely get a little bit of rain today, though the highest rainfall totals are expected in areas south of the Missouri River as the track of the shortwave takes the focus for precipitation more into southern Missouri. Therefore have adjusted POPs and QPF to reflect the more southern solution that current short range models and radar trends advertise. Severe weather is not expected as our area will be on the "cool side" of the shortwave, thus not nearly as much instability as there could be with 0-6KM shear values generally staying under 25 knots. Only portion of the forecast area where the shear and instability might be able to conspire together would be across our far southwest corner; east central Kansas into far west central Missouri south of Kansas City this afternoon. Shear values in the late morning and afternoon increase into the 30 to 35 knot range as the shortwave moves though, but it is expected that instability will be rather poor owing to the convection and cast off precipitation from this morning. As a result, expect much of the activity for storms to pass across southern Missouri though the morning and afternoon hours with the potential for precipitation fading in the evening hours. With the passing of the eastern Kansas shortwave today the region should be able to dry out a little tonight and through the day Thursday as the ridge to our west flattens out some and expands into Missouri. This will push temperatures back up, but still leave conditions rather nice for early August. However, the chance for storms will quickly return Thursday night as the Canadian border shortwave slides into the Upper Great Lakes. Enhanced moisture transport on the nocturnal jet may be able to get storms percolating across the region again. Otherwise, expect the chance for storms to persist through the weekend as the flattened ridge remains across the Plains States, resulting in a repeated potential for storms as various shortwave troughs run the ridge crest just to our north. Currently, Sunday looks to have the best chance for some kind of organized storms as it looks like a stout trough moving through the Northern Plains will force a cold front through Kansas and Missouri sometime Sunday. Additional implication from this is that it might be a bit warm and muggy Friday and through the weekend, but that temperatures will back off a little going into Monday. && .AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon) Issued at 1240 PM CDT WED AUG 5 2015 Main concern for the short term is MVFR cig/vsby as moisture only slowly moves east and south. Currently the terminals have cigs around around 1000 ft except at KSTJ where the sky condition has cleared. The RAP13 and HRRR models introduce some surface based instability so we should see some return of clouds with a few VCSH after around 21Z through around 03Z. This instability will be rather weak and given sunset will drop even further so not going to carry CB at this time. As drier air moves in late tonight...the clouds will scatter out but some trapped ground moisture from recent rain will provide some MVFR vsbys until around 14Z tomorrow morning when VFR will prevail for the remainder of the period. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ DISCUSSION...Cutter AVIATION...Adolphson