yoda

Also Friday and Saturday Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0404 AM CST Tue Dec 28 2021 Valid 311200Z - 051200Z ...DISCUSSION... ...Day4/Friday - Arklatex to the Mid-Mississippi Valley... A mid-level shortwave trough will move from near the Baja Peninsula Friday morning to the southern Plains by late Friday night. This approaching shortwave and deepening lee cyclone across the southern High Plains will elicit a strong mass response across the Arklatex late Friday and into Friday night. As the low-level jet strengthens, storm coverage is expected to increase in a broad zone of isentropic ascent north of a warm front from southeast Oklahoma to the Tennessee Valley. In addition to this elevated storm activity, most guidance also shows surface-based storm development on the warm side of the boundary Friday evening into the early morning hours Saturday. A very moist boundary layer will be in place ahead of this storm activity with mid-60s dewpoints as far north as southern Kentucky at 06Z Saturday. Therefore, convection will form and propagate into an unstable environment which will allow thunderstorms to continue through the overnight hours and into the Day5 period with a severe threat throughout. Strong deep-layer and low-level shear will support all severe hazards. ...Day5/Saturday - Mid South and the Tennessee Valley to the Southern Appalachians... Severe weather will likely be ongoing at the beginning of the period from the early morning thunderstorms across Arkansas and vicinity. There may be a slight lull in storm coverage/intensity during the diurnal minimum Saturday morning, as the lead wave continues northeastward and the primary trough approaches from the west. However, by midday, significant height falls will start to overspread the warm sector and widespread storm development is anticipated. The location of overnight convection will have a significant impact on the zones within the broader risk area where a higher severe weather threat will exist. However, all guidance shows a broad warm sector with a broad 50 knot low-level jet, which would foster an environment favorable for all severe weather types. The greatest uncertainties are related to the northward extent of the risk and the surface low track. Given the widespread convection expected north of the warm front, a convectively reinforced warm front could set up farther south than the surface low track may suggest. Also, global guidance still varies with the intensity and location of the surface-low as it tracks northeast. The track and intensity of this surface-low will have some impact on the storm evolution and intensity within the warm sector, especially as it relates to storm mode and the tornado threat. Maintained 15 percent probabilities from the previous Day 6 forecast with an expansion on the southern and eastern extent to account for the threat continuing late Saturday night.

Large SLGT risk from TN into the mid South for Day 2. Interesting re the bolded below Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1257 AM CST Tue Dec 28 2021 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-SOUTH AND TENNESSEE VALLEY... ...SUMMARY... Severe thunderstorms are possible for portions of the Deep South into the Tennessee Valley. Large hail, damaging winds, and a few tornadoes will be possible. ...Synopsis... A mid-level shortwave trough can be seen off the Oregon coast early Tuesday morning. This shortwave will round the base of the large-scale trough to near the Southern High Plains by 12Z Wednesday and into the northern Great Lakes by Thursday night. This will overspread weak height falls across the warm sector during the day Wednesday. Meanwhile, a lee cyclone is expected to develop near the Oklahoma Panhandle Wednesday morning and move quickly eastward along the surface front through the day. Guidance has come into better agreement showing a closed surface low developing along the front, but there still remains some uncertainty in the exact location and strength of this surface low. ...Portions of the Mid-South and Tennessee Valley... A long-fetch Caribbean moisture feed will be in place across the Southeast on Wednesday morning with mid-60s dewpoints into southern Tennessee at 12Z. Low-level flow will strengthen in response to the developing surface low along the front Wednesday afternoon. This will advect higher theta-e air northward with mid 60s dewpoints into north central Tennessee and upper 60s dewpoints into portions of northern Mississippi and Alabama. Some breaks in the clouds are anticipated in this region as low-level cloud streaks advect northward across the warm sector, which may allow temperatures to warm into the mid to upper 70s. As a result, ample instability is anticipated across the warm sector, with MLCAPE in excess of 1500 J/kg possible as far north as Columbus, Mississippi. Thunderstorms will likely be ongoing at the beginning of the period near the Red River in southeast Oklahoma/northeast Texas in response to increasing isentropic ascent as the low-level jet strengthens. This activity is expected to continue northeastward through the day and may eventually overspread the warm sector, and become surface based. The marginal and slight risk have been expanded northward to account for this possibility given the favorable severe parameter space across much of the warm sector Wednesday afternoon. The primary severe weather threat will be focused on thunderstorms east of this activity in a region of broad, weak isentropic ascent where a confluence band could set up off the Gulf of Mexico. Expect storms to develop out of cloud streaks which will be streaming north through the morning. 00Z CAM guidance appears to be subdued in reflectivity and updraft helicity depiction. Forecast soundings in proximity of this convection would suggest more intense storm development than is currently shown. CAM guidance has had similar issues in past cool-season Southeast severe events, and therefore it could be a false depiction of storm intensity based on the environment. However, there are times when lackluster CAM reflection of storm intensity is hinting at a greater problem with forcing. This is at least somewhat of a concern given the mostly neutral height tendency across the region for much of the event. Any storms which develop in this region will encounter favorable vertical shear for supercells with effective shear in excess of 50 knots. In addition, the weakly forced nature of the convection will likely favor a mostly discrete storm mode. These storms should have a tornado threat, given the strengthening low-level jet, with a broad region of 40 knots of southwesterly flow at 850mb depicted by most guidance. This will yield effective SRH around 250 m2/s2 which will be more than sufficient for a few tornadoes. An upgrade to enhanced (10%/sig) was considered across northern Mississippi and northwest Alabama, but ultimately settled on an expansion of the slight risk for this outlook. If guidance continues to trend toward a stronger surface low, and if CAM guidance starts to show more intense storm development, an upgrade to enhanced may be necessary. ..Bentley.. 12/28/2021

Gradient pattern to end the run... and SE ridge is flexing us on to the wrong side this run

Until it blasts a huge cutter right after lol With another major arctic dump behind it

00z CMC has a major rain to snow storm at the end of its run - January 2 to 4th time period... 2 to 4 inches lol

Is that something on Day 10 on the Euro? Or nah?

That was an lol ending to the 00z GFS in the Uber long-range

Impressive

h/t @griteater... borrowing this from the SE forum

00z EURO is actually intriguing Day 5. Would be rain, but coastal low is much closer

Hmmm

Sorry to hear... hope everything is okay with your dad

Get that HP a bit further west and we in business

At least we got it to Day 7 lol

H/T @North Balti Zen Posted in our subforum... reposting it in here

Thats just infuriating

Who's ready for a Jebwalk?

Can someone explain this please? Thanks :)

06z GFS has snow for early next week

Lol CMC would be power outages with major ice and heavy wet snow... if it were to even happen

Looking intriguing near Clifton Well it did for a frame lol

Watching the Centreville to Manassas line

H/t @ORH_wxman

https://fox2now.com/news/live-updates-search-and-rescue-underway-at-amazon-facility-in-edwardsville/

Welp https://fox2now.com/news/live-updates-search-and-rescue-underway-at-amazon-facility-in-edwardsville/