andyhb

We have a landfall per radar. Center is onshore.

This will not be a Tacloban storm surge. Maria is not as big as Haiyan was in size nor has it been an intense hurricane for nearly as long as Haiyan was prior to landfall (i.e. two of the most important aspects for building a large storm surge). There is no need to excessively hype an already dire situation.

Yes I can't disagree with that either. If that was the case, we'd now have 3 Cat 5 storms (2005 had the most with 4).

Keep in mind with those stats above that we still have all of October to go through, which typically has more storms form in the Caribbean, which has essentially been untouched despite the explosion of activity since late August (exceptionally favorable TCHP). Onset of La Nina conditions in the Pacific only suggests more potential with anomalously weak shear. Oh and with Maria now being a Cat 5 based on recon, this may be only the second Atlantic season on record to have two Cat 5s make landfall (2007 with Dean and Felix).

In terms of statistics, we're starting to creep towards some records in terms of high end activity for a single season. Maria's the fourth Cat 4+ of the 2017 season, 2005 is tied with 1933 for the most with 5 (Dennis, Emily, Katrina, Rita, Wilma). Also Maria may be the the 3rd Cat 4+ to make landfall this year in the Atlantic, 2005 again tied with 1933 had 3 with Dennis (Cuba), Emily and Wilma (both Yucatan).

Well, an eyewall replacement cycle given the eye is quite small and will interact with complex terrain in a few hours.

Its highest peak is almost 1500 m elevation, despite the small size of the island, that will have a temporary effect.

Recon might miss its peak given the core is likely to interact with the mountains on Dominica before the plane arrives.

Pending enough moisture return, Tuesday (9/19) could offer a fairly substantial severe risk across the Dakotas mainly. Consensus for a strong, negatively tilted shortwave pivoting east/northeast out of that large trough in the northwest with a broad, 40-50 kt southerly/south-southeasterly LLJ axis becoming established by 21z Tuesday. Don't see many problems with forcing for ascent (so much so that fairly quick linear transition is more of a concern than a cap bust), and if enough southwesterly 500 mb flow can overlap the LLJ axis, deep layer shear shouldn't be an issue either. Seems to me like it could be the first healthy risk of the "second season". Also, the primary trough/ULL remains in the west in behind, which could lead to further potential later in the week, although that's still TBD.

Now it is after the upgrade from what I've seen. Looks like it is hammering Puerto Rico as a Cat 4.

Yeah I think we have Maria at this point. That's a well organized COC.

Not a bad call. Initiated about 15 miles E of Mitchell.

I get the sense that there may be a surprise or two in E SD (perhaps somewhere in the Mitchell vicinity) this afternoon/evening looking at the overall synoptic setup. Pretty healthy dynamically in the low levels with favorable proximity to the triple point, although deep layer shear is a bit marginal for supercells.

Evening model runs looking pretty interesting over the E TX Panhandle and west-central/SW OK tomorrow. 00z soundings show high quality BL moisture in place over the source regions (FWD, CRP, BRO). Even OUN has an 11-12˚C H85 dewpoint. Most of the VBV showing up in the soundings by 00z looks to be above 500 mb, which is another plus. Steep lapse rates showing up over the EML source regions for this setup. Barring a very significant increase in convective coverage tonight, I think we should see a fairly healthy warm sector tomorrow afternoon. Going to be dependent on the western branch of the low level jet strengthening sufficiently for higher tornado chances though, but synoptically speaking, it looks like one that could yield a few tubes.

Georgia has gotten absolutely raked this year. It has fit with an overall SE shift closer in to verification with a lot of the threats through April.

12z CAMs, particularly the NSSL WRF, highlighting the possibility of intense supercells INVOF the I-10 corridor through the afternoon tomorrow.

Surprised there hasn't been a bit more discussion for tomorrow in SE TX and LA. The GFS, Euro and NAM variants are all suggesting a relatively high end (particularly in the low levels) parameter space in place centered on the Sabine Valley and then shifting E towards the Lower MS Valley later on, especially nearer to the warm front. Assuming the MCS along/ahead of the southeastward moving front doesn't completely take over, seems like there would be potential for tornadoes out ahead in the open warm sector. 00z NCAR ensembles did show a number of members with more discrete cells going up out ahead of this feature.

Looks about ready to go in the NE TX Panhandle (GOES 16 data via COD).

That should change later on as the vort over the NM/CO border shifts east and the surface low deepens over the western OK Panhandle. Mid 60s dewpoints over SW OK right now via the mesonet, should be game on if those get anywhere near the triple point.

NCAR ensemble (which performed quite well yesterday) was also pinpointing that area for a heightened risk. Sitting right on the southern periphery of the vort max passing to the north with slightly strengthened flow aloft as a result. There's a plume of low 60s dewpoints lurking to the south with 8.5-9+ C/km 700-500 mb lapse rates over the region currently, those two combined should yield some impressive CAPE later on. Low level flow doesn't look quite as favorable (strength wise) as it was yesterday, although there is certainly some decent veering in the lowest km.

That big one was down for at least half an hour unless it cycled in between scans. Certainly not something I saw coming today, but favorable low level winds can lead to strange things when combined with 2500 J/kg MLCAPE. Noteworthy that the 500 mb flow was only around 15 kts in the area where this cell set up shop.

Yeah I'd say this cell is enjoying its environment just a bit.

160+ kts GTG, wedge in progress from Daniel Shaw's stream.

Little bit of Panhandle magic going on W of Dimmitt right now, already one short-lived tornado confirmed and looks to be cycling to the south. Overall synoptic setup today reminded me a lot of 5/22 last year, which yielded several slow moving tornadic supercells (thermos obviously not quite up to that level).

Positioning of subtropical ridging is going to have to change here. It's anchored too much over the central US shunting the storm track north (almost reminiscent of a late June/July-type pattern) before any shortwave can eject into the Plains. Need to get that shifted east. So far this year, the Pacific jet has been overwhelming these western/central US ridging episodes with time. The cycles in AAM/MJO activity have been driving jet extensions generally towards the tail-end of the months. Some of the mid-range ensembles are generally indicative of this occurring again, but probably don't want that ridge to become too dominant in the meantime.