nrgjeff

ECMWF comes out after the Day 2 from SPC. Evidence now supports a slight risk Saturday from North Alabama into North Georgia. NAM and Euro both have a lot of CAPE along and south of a lifting boundary. I thought the 12Z NAM was nuts showing a right mover there; other CAMs do not. Now.. Euro introduces a mesolow on the said boundary. Low level winds are veered off, and the upper levels are not robust. However it's May which is CAPE season. While the Day 2 update is still Marginal, I figure on waking up to Slight. No I'm not staying up, lol! Something to watch Saturday though.

The period from May 17/18-ish for 7-10 days looks very active in the Plains. This 500 mb chart forecast is accompanied by strengthening upper level jet stream from the WSW and LLJ response most days from the straight south. Tee. It. Up!

Thursday morning: Slight kink in surface wind trajectories is noted on the TN/KY border. Boundary occasionally shows on visible satellite. However both sides are pretty veered off. MCV is approaching so I expect the Slight verifies for mainly wind. Deep layer shear is meh. However low level shear is OK, esp on the boundary and straight east of the MCV. Probably not a big deal, but it's something to talk about in our Region. Otherwise I think the seasonal progression toward the Plains is on-track. They had quite a week!

Let's forget about snow this winter, and just have Dixie Alley going for 6 months straight.

ECMWF verbatim May 4 will be Bennington 4.0 but it's Day 10. EPS and GFS keep the train rolling in the 11-15 day. Weekly models (no skill after week 3) have more action the rest of May. MJO and AAM trends are forecast to be friendly. We'll see. One example of nice real data is Japan's Himawari satellite loop. West Pac convection is starting to lose influence as the Indian Ocean flares up. Buffet line of mid-latitude systems is noted from East Asia across the Pacific Ocean.

Next 7-10 days will struggle. GOM trajectories point to the Caribbean, not the Mainland. That's a problem! Could perk up a bit 11-15 day period. More troughing is forecast out West. Going into May moisture will be more predicable too. MJO is trying to improve. Indian Ocean is waking up. Still junk in the West Pac though. Some models rush the latter through and reset toward week 3. Others let the IO start to influence sooner. Either way I can't argue with climo. Should pick up by mid-May.

I'm far less optimistic than the Twitterverse. While the IO is flaring up as expected, the West Pac remains active too. Signal conflict. Expect mixed outcome in the USA. I'm pretty bearish next 15-20 days. Perhaps it switches around for late may peak of climo. I ain't holding my breath. It'd be Plains anyway. ECMWF weeklies flipped from good to poor about next week a year ago. I'm expecting a repeat. Sorry I am so jaded. Too much early season VBV garbage.

Another year without snow in CHA. Farther west the Plains and Mid South cash in.

TNI is backwards. Cancel rest of severe season. Today is a great example of crap setups.

Glad nobody started a thread. Today does not deserve one. My first day back since Sunday.. HRRR seems odd with heavy stratoform precip. NAM tries to fire off the back side of line later this evening. LOL at that solution with LLJ cut off and stable atmo. Line may spit out some straight wind later this afternoon; then, weakens. South Bama could keep going. Spann may have a long night. Up here I'm not too concerned. Looking fwd to watching more NBA playoffs.

Saturday it now appears supercells will make it east to the Delta (flat no trees) of east Louisiana and southeast Arkansas during daylight hours. Euro/NAM have a slow bias and even they put it in range. GFS and ARW (research version of WRF) has always rocked the Delta. SPC seems to agree. Detailed discussion is in a Central/West thread.

Event thread for April 13-14 weekend severe wx outbreak is in Central/West. Thread subtitle includes Mississippi, my likely chase target Saturday. My thoughts are in that thread. Basically with less morning rain in Mississippi, the warm front should lift north more. I expect discrete cells along the WF and/or outflow boundaries.

SPC 30% looks good for MS/AL Saturday. Winds turn with height gradually which creates rather classic forecast hodographs. Low level turning is notable. Instability will rapidly increase as the warm front lifts north. Storm mode will be sloppy along the pre-frontal trough. However discrete supercells could/should develop along the WF in LA/MS/AL. Overnight Saturday night looks ugly on the ECMWF. Holds supercells, almost a line of pearls, overnight. Much as I like storms and chasing, I'm rooting against that overnight crap.

Palm Sunday is the elephant in the room, so I'll address it. It's Day 7. Done. OK seriously, the GFS verbatim only shows ENH due to unidirectional winds, lots of rain, and likely coastal MCS. ECMWF verbatim is MDT no sugar coating it. However neither are high, thanks to moisture concerns, and possibly energy ejecting too far north. Still Day 7 so lots can change. Might end up Marginal, lol. Ways to get there include heavy rain on unidirectional winds or some sort of Gulf MCS. Little closer in I figure Thursday will have moisture issues. Upper dynamics displaced too far north. Maybe low-top Illinois Indiana but that's another subforum region. And today? I think those Gulf thunderstorms don't qualify as enough for an MCS bust. SPC leans toward it weakening (MD 287) which would keep North Alabama in business later. CAMs are weak with low level shear; but, pattern recognition shows outflow boundary east of surface low. Dixie gonna Dixie? UPDATE: Central Alabama BHM south, which is out of our regional subforum. NCAA Final is my evening plan.

Come Monday it'll be alright. Come Monday I'll be holding shear tight. -Jimmy Buffet with some Jeff at the end. Sunday still looks like a mess. Storms in Middle Tenn are trying to create their own LLJ but warming 700 mb will end the party. Just hope the non-severe junk holds off for my Sunday outdoor plans in Chatty. Monday looks intriguing in northwest Georgia, but that terrain! Low level shear should be good east of the surface low and triple point. Upper shear is suspect. Reminds me of June around here. IDK if it's worth a chase. Maybe hang out on the view deck of Ft Mountain State Park and hope to see something.. without getting struck by lightning! Might be better to watch the NCAA National Championship on Monday. Go Texas Tech!

Late April we hope that awful convection in the West Pac dies. Some models forecast the IO to refire, which puts the North Pac ridge in the correct place for a West USA trough. Unfortunately those week 4-6 forecasts have practically zero correlation to actuals. We hope though! Plus May climo is trough West. As for this weekend: NCAA games and Chattanooga Football Club.

HRRR tries to get supercells going on the warm front in Mississippi on Saturday. No other CAM (I've seen) agrees. Warm mid-levels. Erratic upper level winds (bad hodograph). Bulk shear is good and so is instability. However I'm real skeptical of anything but a messy blob. Good news for folks who don't like intense severe. Though some wind/hail is likely.

Sunday the ECMWF shows another Gulf MCS keeping Dixie Alley quiet. ECMWF continues a Texas MCS which might not exactly dive to the coast. ECMWF upper levels are suspect, but match the surface scenario. The following is based on the GFS/NAM. 'Murica yeah! The 200/300 mb level winds are little weak and erratic; however, 500 mb is robust and more west than south. Otherwise surface to 700 mb shows pretty good turning. Hodograph is a mess above 500 mb; but, it looks great from 700 mb down. Instability is forecast across Mississippi and Alabama into Georgia. I'm not sure about Tenn. Pattern recognition and some models have a boundary lifting through Alabama. It's left over from the Thursday/Friday system. Front never makes to the Coast. It should lift back as a warm front with quality moisture. Sunday is being monitored for a possible chase. If the ECMWF is right I'll instead be relaxing with family in Chattanooga, lol!

Thursday looks like a mess with JIT moisture and a monster MCS cutting off everything anyway. Weekend (Sunday?) looks better. Moisture will already be in place as the Friday front never clears the Gulf. Upper winds may have VBV issues; but, at least it'll be more unstable.

Thursday severe weather is possible in southern Mississippi. Models forecast adequate speed and directional shear. Appears moisture will be there in time, especially I-20 south. I would focus on the lifting boundary showed by both conceptual models and numerical models. Morning rain is forecast in northern Mississippi. Should keep a lifting warm-front like feature defined. Pre-frontal trough comes in from the west ahead of the cold front, key for robust severe. Right on the cold front is usually trash. Prefrontal trough can be better. Intersection of those boundaries is currently forecast in central Mississippi. More rain would push it toward I-20. Less rain would put northern Mississippi in play.

Probably climate change as we lose the ocean sinks. Oops wrong sub-forum! We are still behind the ENSO spring predictability barrier. Who really knows what will happen next winter? In the mid-term the MJO is a disaster right now for severe. Japan's Himawari satellite loop shows nothing good either. Hopefully it does change by mid-April.

Glad I stayed home and watched basketball this past weekend. Upcoming Thursday I'm not nearly as impressed as SPC. Just-in-time moisture fails in April, kind of like Fed-Ex drivers running you off the highway rushing their JIT deliveries. Wind shear (speed and directional) is good southern half of Mississippi. However that's almost out of our Region and more Southeast sub-forum. Hopefully Wichita State will be playing in the NIT Final Thursday; so, I'll likely be home.

Nashville sounds bullish. Moisture return is slower than models have though. Waze app (Google maps) reports repeating multiple accidents I-24 West of Chattanooga. I'm not sure it's rubbernecking, road rage, or both. Regardless I'm not dealing with that on my way. No storm chase today. NCAA starts in a couple hours anyway.

Moisture return is still meh. However temps will get well into the 70s. Perhaps it's a good trade-off. Limit tornado risk, but good visibility if anything happens. Upper winds are OK. Low level turning is barely at threshold (IMHO). It's borderline, but it's also almost April.

For severe, per TNI, we could use warmer 1.2 and milder 3.4. Otherwise early severe was a head fake. I still think this KW and other factors (persistent Heartland storm track / Baja SSTs) will bring more action.