Area Forecast Discussion
Issued by NWS Springfield, MO
Issued by NWS Springfield, MO
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553 FXUS63 KSGF 050102 AFDSGF Area Forecast Discussion National Weather Service Springfield MO 802 PM CDT Thu Jul 4 2024 .KEY MESSAGES... - A Heat Advisory is in effect for far southern Missouri through 9 PM with heat index values ranging from 100-105 degrees. - There is a Slight risk (2 of 5) for severe thunderstorms across much of the area this evening. Damaging winds will be the primary hazard. - Storms this evening will produce efficient rainfall rates resulting in a risk of localized flash flooding. - Cooler conditions return Friday into next week. && .MESOSCALE... Issued at 801 PM CDT Thu Jul 4 2024 A surface cold front continues to slowly move southeast across the Missouri Ozarks. As of 8 PM, the front is analyzed from Neosho to Nixa to near Houston. Weak height falls are overspreading the region which will support the front continuing to slowly move southeast throughout the remainder of the evening. Deep moisture convergence will continue to increase along and ahead of the front and will support continued development of scattered thunderstorms. The greatest coverage of storms will initially occur across southwestern Missouri through 9 PM. This activity will then expand and shift northeast along and south of the I-44 corridor through midnight. Most of the activity will exit the eastern Ozarks by 09Z. The 00Z KSGF sounding indicates that the environment is highly unstable with MLCAPE values over 3200 J/kg with virtually no inhibition. Low-level theta-e differentials over 30K will be supportive of localized damaging wind gusts with the initial scattered activity. Deep layer shear of 25-30 knots and expected cold pool conglomeration may result in some upscale growth into linear clusters. This would correspondingly enhance damaging wind potential in the 02 to 05 UTC time frame if the upscale growth does indeed occur. A few storms may also produce hail to the size of quarters. We will also be monitoring the potential for locally heavy rainfall and localized flash flooding as precipitable water values remain in the 1.7-2.0" range with rather slow storm motions. We are going to leave the ongoing Flood Watch as is given that this activity will shift into much of the watch region over the next few hours. The western extent of the watch may be cancelled early if storms remain to the southeast of that particular area. && .SHORT TERM /THROUGH SATURDAY/... Issued at 204 PM CDT Thu Jul 4 2024 Afternoon temperatures have climbed into the upper 80s to lower 90s. Combine with dewpoints in the lower to middle 70s, heat index values were in the 100 to 110 range, especially across southern Missouri. This heat and moisture will set the stage for potential shower and storms development late this afternoon into early this evening. CAMS continue to struggle with initiation across the Ozarks but do indicate the potential for showers and storms to begin developing across far eastern Kansas and Northeastern Oklahoma between from 21z this afternoon onward (more likely closer to 22-23z), depending on the model of choice. CAPE values in the 2500-3500j/kg range were in place across the region. As an upper level trough moves across the northern plains and a surface low in Oklahoma begin to shift east a cold front will begin to make its way into the region this evening and overnight. With the expected frontal lift and no cap, showers and storms are expected to develop mainly west of I-49 and move east through this evening. While there looks to be limited low-level Jet support for storms, with the front moving towards the region, and upper level jet energy across northern Missouri providing some upper level support, some storms will be capable of becoming strong to severe. The main concern remains damaging winds with D-CAPE (downdraft CAPE) of 1000-1400j/kg supporting this. Hail potential is less concerning, but 500-900j/kg in the hail growth zone (-10 to -30 degree level) and 35-40kts of 0-6km shear would allow for isolated large hail. The tornado chances are rather low though not zero and will rest on how storms develop and move east this evening. Will also monitor for flood potential with PW values in the 1.7 to 1.9" range noted across the region. This will allow for heavy rainfall potential, which may have impact across areas that received rainfall last night. Additional rain amount around an inch with locally 2 inch or higher amounts will be possible with storms as they move across the region this evening. Thus, the current Flash Flood Watch continues for this evening. Showers and storms will push south and east of the region overnight with clearing skies behind the cold front occurring by sunrise or earlier. Cooler temperatures will filter into the area behind the front. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... Issued at 204 PM CDT Thu Jul 4 2024 From Friday onward, temperatures will return closer to annual climatology, with highs in the 80s for the rest of the week as a cooler and drier airmass moves over our area. Precipitation chances return Sunday night as a shortwave trough over the Great Plains moves south. Both the 12z GFS and ECMWF develop convection over the southern Great Plains Sunday afternoon into Monday morning, and there is some model support for a possible MCS that develops north of this convection that may move into southeast Kansas and southwest Missouri. Confidence in the exact details of this event will become clearer as we approach it. For now, precipitation chances are set from 50-70%. Early next week, ensembles show a pattern of upper-level ridging developing across the western U.S. This will put us in a regime of northwesterly flow. Precipitation chances for the rest of next week currently sit below 30%. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Issued at 618 PM CDT Thu Jul 4 2024 A passing cold front will bring scattered thunderstorms to southern Missouri this evening. The main impacts to the terminals will occur between 01 and 06 UTC. IFR visibilities can be expected beneath thunderstorms along with gusty and erratic winds. The storms will then shift southeast of the area late tonight with VFR prevailing into Friday. Surface winds will remain out of the northwest through Friday with afternoon gusts around 20 knots. && .SGF WATCHES/WARNINGS/ADVISORIES... KS...Flood Watch until 1 AM CDT Friday for KSZ073-097. MO...Flood Watch until 1 AM CDT Friday for MOZ055>058-066>071- 077>081-083-089. Heat Advisory until 9 PM CDT this evening for MOZ093-095>098- 101>106. && $$ MESOSCALE...Schaumann SHORT TERM...Hatch LONG TERM...Hatch AVIATION...Schaumann