RAP pre-storm

-tvguy

Looked at GOES total PW. Amounts >1" from eastern UNR CWA into western ND and far eastern Montana... pretty decent for this area. Unfortunately, the surface obs are still pretty dry in the western Dakotas, with dew points only in the 50s - for now - though there is a southerly wind for most everybody.

NUCAPS total totals were uniformly 50-59 north of Rapid City to the Canadian border.

Looked at cloud optical depth to get some idea about the thickness of the cloud cover in the central CWA. Appears to show cloud cover is thin, so I assume we should get strong solar heating this afternoon.

By 21Z Cu field approaching NW corner of SD. Queried recent NUCAPS grids to check 700 mb temps, which were 12-14C.

At this time, SPC issued t-storm watch for NW corner of SD, but mostly for western ND.


But also looked at NUCAPs 850 Lapse rate... over 8C/km. Expect that if these towers in western MT move into that area, they should blow up pretty quickly.
1 min VIS puts storms approaching NW corner... with 1 min GLM flash points increasing quickly.

When looked at same flash data, they was well out ahead of the main line of storms on radar.

Bismark CWA - Derived Stability/Moisture Data Analysis

Quick look at some of the derived parameters sat 1857 UTC prior to expected storm initiation today.  Following image has the following parameters from upper left to lower right : Total Precipitable Water, CAPE, K-Index, Lifted Index.

TPW fields indicate some moisture pooling to the west of ongoing convection, with a similar trend in the instability fields. Drier, more stable air in place upstream of developing storms. Unsure if this just indicates where current forcing/ascent is and this will translate eastward or if current storms moving into less favorable environment.

CAPE values continue to be significantly lower than numerical model analysis, but LI values much closer and seem reasonable given the pattern.

-JRM

UNR Satellite Analysis

A loop of upper, mid, and lower level water vapor along with a simple water vapor RGP indicates an area of potential lift crossing south central MT (top right). The RAP indicates a 50kt 500mb wind maxima lifting through this area, and GOES-derived winds suggest the core of this wind maxima may be displaced a bit further north and east in the model. The wind barbs do seem to drop in and out with each frame. Not sure if this is a sampling issue or what.

Visible imagery (not shown - CAVE is locked up) shows an area of convection over south central MT associated with this jet streak, and the day cloud phase RGB indicates this area has become glaciated.

Anticipate this activity will continue, and likely grow in strength as it moves into deeper moisture further east.

-64BoggsLites

Bismark Early Phase Convection

The RGB Day Cloud Phase is indicating some vertical development/introduction to some cloud glaciation across western ND. Would expect this to be associated with some shower development, which when pulling up the MRMS data there is evidence of a slight increase in shower activity. This color scale is much better than the eye piercing red and green. I might prefer this imagery over the clean IR window product that I've been using all week to monitor cloud top cooling.

Week 4 Day 4 Operations

Forecasters today will wrap up the week operating in the Bismark, ND and Rapid City, SD CWAs.

-Michael

Day 3 Wrap Up and Feedback

Day 3 saw forecasters operate in the Melbourne, Fl CWA all day monitoring some weak sea breeze convection, and in the Sioux Falls, SD CWA monitoring an initial MCS and later some strong storms forming off of the remnant outflow boundary. Discussion feedback is posted below:

GLM

Seeing the anvil lightning was really cool to see how far the extent of lightning can be from the parent storm

Saw GLM flashes and NLDN CG flashes ~90 miles from storm core

In Florida it was easier analyzing the storms using the flashes to keep the storms separate from each other

Looked at different grid resolutions and the 9 - 10 km resolution seemed to work best

5 km resolution was to “pinpointy”

Events made the most sense to use over groups

Liked the Stano test color curves as the easiest to look at quickly and pick up the trends and hot spots

Parallax issue would probably be a big issue in the field

First impression is a big deal, and the parallax issues should be fixed before fielded in the offices

Much rather have the GLM combined and color curves here to use in the field, it’s much more intuitive

NUCAPS

No gridded data in Florida

Sounding were a lot better representation of the atmosphere yesterday than previous days

Showed a bit of a weaker cap in the gridded data than the RAP and the cap did end up breaking shortly after

Very useful for initiation yesterday

Having more passes the better, especially in the early afternoon time frame

Soundings are consistently doing pretty well above the boundary layer

Like having the option for both the operational and the experimental soundings depending on the boundary layer environment

ABI

“I like it”

Monitoring for initiation was nice for monitoring for glaciation

Cumulus field turning to stratocumulus showed a capped environment

Day cloud phase RGB shows glaciation really well

Used the 3.9 yesterday to pick up some thermal difference

Obviously not all bands are going to be used by themselves

None of the other bands really jumped out too much with the pulse convection

Low-levels of derived winds have very little information

ProbSevere

A couple of large ProbHails in Florida that seemed a little unreasonable for the tropical environment it was in

ProbTor highlighted the part of the bow that was most intense and capable of tornado production

It highlighted the part of the line that was different

Some of the tracking, especially on lines needs some work to be useful in line events

Overall it’s a great tool that seems ready to be used in operations especially as a SA tool

It forces you to really interrogate the storms of interest to see what is going on

Helpful for people with lower radar experience to fall back on for interrogation

-Michael

Another Anvil Lightning Event - Near Akron Iowa

GLM picked up another case of anvil lightning at 2341 Z near Akron Iowa.  CG occurred at same time as GLM events were noted, so no real lead time to this strike was observed. Image below of accumulated 5 minute GLM event density and flash data updated every minute along with the NLDN CG strikes.

For reference this image indicates how far the main area of storms was from lightning strike (white dot). There were some 30 dbz echoes near Vermilion SD but they never grew much stronger than that during this period. This was around 90 miles from main storm area.

-JRM

Anvil Lightning-Near Yankton

Interesting to see a cloud to ground lightning strike occur well away from main updraft cores in area with little if any meaningful reflectivity. Following loop is focused on the Yankton area, well removed from the main cells of thunderstorms. Image is a combination of GLM  5 minute accumulated event density and MRMS 1 km composite reflectivity.

A couple of things stood out to me. First you see the area of GLM areas of GLM events extending over the area followed by a few flashes, followed by a NLDN positive strike southwest of Yankton.  The following image shows how far away that was from main core of storm. White dot represents location of positive cloud to ground strike.

-tvguy/jrm

JAX Pulse Storm

In the JAX CWA, a storm seemed to intensify along a shear zone which was detected well in the upper level water vapor imagery. The intensification was noted mostly via rapid cooling of the cloud top temperatures seen in the IR imagery as well as the 1 min update of the GLM flash density at 8km. I forgot to load the PROBSevere before saving this image, but PROBhail did increase to 30% for a scan or two (which was very good for us today)

Advancing Outflow Boundary - FSD area

Following loop indicates what appears to outflow from earlier MCS advancing to the south across southern portion of the CWA. Interesting to see it interact with area of cumulus. Can see cu field increase as feature passes. Also gives some indication of overall stability as clouds seem to form into more of a stratocumulus deck with no deep vertical development observed. Increased resolution made it much easier to see reaction to this forcing.

JRM