Area Forecast Discussion
Issued by NWS Memphis, TN
Issued by NWS Memphis, TN
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145 FXUS64 KMEG 241700 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 1200 PM CDT Fri May 24 2024 ...New AVIATION... .UPDATE... Issued at 1025 AM CDT Fri May 24 2024 As of 10AM, radar imagery depicts showers and thunderstorms situated east of the Mississippi River. Severe weather probabilities at this time remain low due to lack luster lapse rates across the Mid-South. The greater threat with this activity is flooding as rainfall rates of 3 inches per hour have been observed. In addition, several areas have reported flooding of roadways and streams. The forecast becomes a bit unclear past midday as 12Z CAMs have backed off on the redevelopment of storms. However, current satellite trends depict clearing skies west of the MS River. If the sun does manage to peek out for a few hours, the environment will likely recover and additional storm development will be likely. A more favorable parameter space for severe storms will be in place this afternoon. Therefore, any storms that do form could possess damaging winds and large hail. In addition, prolific rainfall rates will remain and further aggravate rivers and streams. Overnight, an additional line of showers and thunderstorms will dive south across Missouri and Kentucky, eventually impacting the Mid-South around midnight. Confidence for this round of storms is higher, but a stout EML at this time should hamper severe storm development. However, elevated precipitable water values will once again aid in heavy rainfall within storms. ANS && .SYNOPSIS... Issued at 429 AM CDT Fri May 24 2024 Showers and thunderstorms will continue to impact the Midsouth through the weekend. Some severe storms will be possible, particularly today and late Sunday. The primary severe weather threats will be large hail and damaging winds. Otherwise, warm and humid conditions will prevail. A few storms will linger across north Mississippi on Monday. Otherwise, fair weather and lower humidity is forecast early next week across the Midsouth. && .DISCUSSION... (Today through Thursday) Issued at 429 AM CDT Fri May 24 2024 The storm track will continue across the Midsouth through the weekend, as a belt of strong westerlies extends from the southern and central Great Plains into the MS River Valley. Under these strong winds aloft, surface dewpoints in the lower 70s will contribute to precipitable water values of 1.5 to 2 inches, and daytime surface-based CAPE nearing 3000 J/kg over the Midsouth. Thunderstorm timing and coverage will be primarily associated with midlevel shortwaves, often enhanced by convection over the southern plains and Ozarks. Similar to early yesterday morning, KLZK radar shows an area of storms with an apparent MCV lifting east-northeast across southern AR. Latest CAMs depict this convection moving through the Midsouth this morning, with isolated afternoon storms developing in its wake. Confidence in coverage area is limited by a strong EML. However, should updrafts overcome the capping nature of the EML, steep midlevel lapse rates (7.0 to 7.5 C/km) will support large hail. With 0-6km bulk shear at or below 30 knots, surface-based convection should wane with the loss of surface heating by early evening. HRRR runs continue to show large run to run variability with thunderstorm depiction beyond 24 hours. 00Z CAM consensus, including the HRRR, depicted storms dropping southeast across AR late this evening, possibly impacting areas around West Helena, AR and Clarksdale, MS. The 06Z HRRR maintains a robust linear MCS from central AR to middle TN, with impacts over the entire Midsouth after midnight. With that said, confidence remains limited with overnight storm chances and potential impacts. The convective parameters are at least supportive of large hail and damaging winds with any storms that develop overnight. Modest shortwave ridging will limit storm organization potential Saturday, but not preclude daytime pulse severe. Stronger westerlies will arrive Sunday afternoon, as the ridge axis lifts to the Carolinas. Surface based CAPE will reach or exceed 3000 J/kg along and west of the MS River Sunday afternoon. This strong surface-based instability will likely be capped under a strong EML south of I-40. This EML will translate east Sunday evening, as height falls and a weak surface cold front lift through the Midsouth. Large hail and damaging winds will remain the primary severe threat Sunday night. Less humid and slightly cooler air will spread into the Midsouth early next week, behind Sunday night`s cold frontal passage. A respite from thunderstorms should last through midweek. PWB && .AVIATION... (18Z TAFS) Issued at 1143 AM CDT Fri May 24 2024 Periods of convection are expected this afternoon and overnight with a much higher confidence of storms tonight. Very heavy rainfall will likely result in brief periods of VFR Vis. Prevailing wind will remain from the south to southwest 5-10kts but could be gusty and variable near thunderstorms. Storms should come to an end around mid morning with VFR conditions prevailing during the afternoon hours. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...Flood Watch through Monday morning for ARZ009-018-026>028-035- 036-048-049-058. MO...Flood Watch through Monday morning for MOZ113-115. MS...Flood Watch through Monday morning for MSZ001>017-020>024. TN...Flood Watch through Monday morning for TNZ001>004-019>022- 048>055-088>092. && $$ PUBLIC FORECAST...ANS AVIATION...JDS