Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/25/20

Area Forecast Discussion
National Weather Service Key West FL
1050 PM EDT Sat Oct 24 2020 .DISCUSSION... The concern for heavy rain over the Keys has lessened over the course of this evening. The warm front-like boundary that was initially expected to hang up and focus heavy precip near the Keys has now moved north of the Keys instead. Though we had a band of transient showers move north across the Keys this evening, it failed to linger long enough over the Keys to bring heavy rain, except for radar-indicated amounts in excess of 1 inch near Tavernier. Each successive run of the HRRR this evening has lowered QPF for the rest of tonight. Have therefore updated the forecast to remove the mention of heavy rainfall and to lower QPF over the Keys through Sunday morning. Tropical Depression 28 formed over the northwest Caribbean late this afternoon. It is currently centered about 400 miles south of Key West. It will move north-northwest and pass through or near the Yucatan Channel around Monday. This path is very comfortably far southwest and west of the Keys, so we will experience no adverse impacts. However, the air mass remains extremely moist for late October, with a PW value of a whopping 2.33" in the evening KEY balloon sounding. Low-level southeast flow on the periphery of TD 28 will continue to reinforce the extremely moist air mass and rounds of showers through about Monday, with some southwest shear across the tropical cyclone streaming mid-upper level moisture across the forecast area. After Monday, the tropical cyclone will move further away from the Keys as it move north through the Gulf, taking much of the moisture with it. More modest levels of moisture currently out east of the Bahamas will trickle in on Mon night and Tue. && .MARINE... At 8 pm EDT, the center of Tropical Depression 28 was located about 400 miles south of Key West. It was moving slowly to the north-northwest and will move northwest through the Yucatan Channel around Monday. On this track, the Keys will mainly experience fresh to strong southeast breezes through Monday. Then an Atlantic ridge axis will build westward across the Florida Peninsula from Tuesday through Thursday, bringing an easing of southeast breezes. && .AVIATION... Scattered showers and isolated thunderstorms will affect the Florida Keys tonight and tomorrow as Tropical Depression 28 moves slowly toward the SE Gulf of Mexico. MVFR cigs and IFR vis can be expected with the passing squalls and wind gusts to 25 knots in the stronger cells. Winds SE at 10 to 15 knots with occasional gusts to 20 knots. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...Haner Aviation/Nowcasts....SDR Data Acquisition.....NB Visit us on the web at Follow us on Facebook and Twitter at:
Area Forecast Discussion
National Weather Service Memphis TN
932 PM CDT Sat Oct 24 2020 .DISCUSSION... Another chilly night ahead of us. Cold and cloudy is the main story for tonight into tomorrow. Lows tonight will generally be in the lower 50s. Latest radar imagery shows light returns, indicating some drizzle might still be present in the Mid-South. No real changes were made to the forecast. SGW PREV DISCUSSION... /issued 332 PM CDT Sat Oct 24 2020/ DISCUSSION... What a difference 24 hours makes? Temperatures are running nearly 35 degrees cooler across the area, in the wake of a cold front. Heavy cloud cover and drizzle have been commonplace across the area for much of the day. Aloft, an exiting shortwave can be seen on GOES Water Vapor Imagery, with nearly zonal flow across the belt of the Central U.S. Latest KNQA radar sweep reveals light reflectivity returns, suggesting light precipitation and drizzle across the area. The latest AMDAR soundings show a pronounced elevated inversion across the region, which will keep this low level moisture locked in through at least tomorrow. Short term...Tonight through Tuesday... Temperatures are expected to remain nearly steady overnight due to drizzle and heavy cloud cover. Expect lows in the upper 40s to lower 50s. Upper level flow will shift more southwesterly tomorrow, as the upper low off the California coast comes ashore. With heavy cloud cover nearly locked in place, temperatures will not warm much. Expect highs to only reach into the low to mid 60s. Expect dry conditions and slightly warmer temperatures to persist into Monday. Split flow over the West Coast will congeal into a large trough by late Monday as it moves into the Desert Southwest Region. Downstream of this feature, a cold front will drop down into the Lower Mississippi Valley and stall over the northwest portion of our CWA. This will keep low-end chances for rainfall in the forecast for areas north of I-40 Monday night and Tuesday, with mostly dry conditions to the south. Long Term...Wednesday through next weekend. The long term forecast has now been complicated by the genesis of Tropical Depression 28 in the Caribbean. This system is now being resolved in both synoptic models as potentially TS Zeta. Both models bring the system up through Louisiana Wednesday into Thursday. This will bring a surge of moisture north into the Mid- South Wednesday ahead of an approaching surface low coming out of the Southern Plains. The remnants of the tropical system and the aforementioned surface low appear to merge as they move through the region on Thursday. This will likely enhance lift and convective coverage across the area, and produce generous amounts of rainfall in its wake. For now, it appears the best chances for rain will be Wednesday and Thursday, with up to 3 inches of rainfall possible. Behind the exiting system, dry northwest flow appears to set up Friday through next weekend. This would translate to near normal temperatures and mainly dry conditions. AC3 AVIATION... 00Z TAFs Ceilings will remain near the IFR/MVFR threshold tonight, more likely below this threshold east of the MS River. HRRR model suggest the -DZ potential may expand to JBR, and increase at the other TAF sites after 06z with a weak impulse wrapping around the back side of the departing upper low. Ceilings will be slow to lift Sunday, as modest surface heating increases the depth of the mixed layer and the overlying thermal inversion base. JBR should see flight conditions improve soonest on Sunday, TUP the latest. PWB && .AVIATION... && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion
National Weather Service Nashville TN
804 PM CDT Sat Oct 24 2020 .UPDATE... FOR EVENING DISCUSSION. && .DISCUSSION... Certifiably yucky evening across Middle Tennessee as WAA continues above the shallow colder air at the surface as shown on our 00Z sounding. Surface obs indicate cloudy skies and patchy fog throughout the area, while radar shows scattered light showers and drizzle mainly across the northern two-thirds. HRRR and CONSShort show light showers will continue this evening but gradually lift out to the northeast overnight, leaving mainly patchy drizzle throughout the area. Have adjusted pops quite a bit, especially over northern zones, based on this thinking and latest radar trends. Temperatures currently range from the upper 40s in the northwest to the mid 50s in the southeast, and they will remain steady or only slightly drop overnight due to continued CAA from the north. Made some minor adjustments to temps for tonight but nothing too notable. && .AVIATION... 00Z TAF DISCUSSION. Poor flying conditions at all terminals now through the overnight hours. BNA/MQY will remain with IFR cigs through the evening. CKV will continue to see periods of -DZRA/-RA through 03Z with cigs remaining along the MVFR/IFR thresholds. BNA/MQY/CKV could have periods of LIFR cigs early tomorrow morning as well as periods of fog. CSV will remain with LIFR conditions through at least the early morning hours tomorrow. Expect fog to develop overnight along with continuing very low ceilings. Ceilings will slowly begin to improve to MVFR at all terminals in the mid-morning to early afternoon hours. Winds will remain light and predominantly from the north through the TAF period. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION......Shamburger AVIATION........Adcock
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