GOES-R CI Probabilities Running Hot...

In a region of high instability (dew points in the low-mid 70's, MLCAPE values >5000 J/kg) the CI probabilities are frequently appearing in the 50-80% range, yet no CI is occurring. A region in far northeastern Oklahoma is highlighted between 2130 and 2215 UTC. Areas further to the northeast in Missouri are, in contrast, showing higher CI probabilities followed by convective storm development.

What is happening?

In these regions, in northeastern Oklahoma, it is speculated that an inversion near ~690 mb is inhibiting CI. Yet, within the CI algorithm, only lower level inversion information is being considered as a variable within the logistic regression equation. This is the suggested reason for the discrepancy between the GOES-R CI signatures/higher probabilities and the lack of storms in Oklahoma. The SPC Mesoscale Analysis (of MLCAPE) is shown below.

The figure below shows the 1200 UTC Springfield, MO sounding shows an inversion near 690 mb. Although this sounding is ~8 hours old, it would seem to suggest the inhibiting factor for the occurrence of deep convection is this inversion. Therefore, from the GOES satellite perspective, the cumulus are growing vigorously, and hence producing high CI probabilities, until this ~690 mb inversion is encountered.

John Mecikalski

Warning based on lightning jump and rapidly increasing flash extent density

This loop shows the progression of the Lightning Jump Detection Algorithm as the storms grow. Also the Flash Extent Density rapidly increased with the storms and subsequently the prob severe probabilities increased as well. Warnings were issued based on the increase in Flash Extent density, because of the usefulness shown in storms north of the Boulder CWA. This tool was extremely useful, as otherwise I may not have notices the rate at which these storms were increasing.

-KP

Blog 7 Lightning jump Detection 5 Sigma

We have seen a 5 sigma light detection jump on the storm in e c Colorado. Our group has warned on the storm.  Cell to the NW has rapid flash extent incr. as well, as severe wx prob increasing. Have warned on it based on these two parameters.

Warned on NW storm on image below. SVR Prob incr rapidly.

Simulated Satellite – Location #3 – CYS

Looked at the simulated satellite imagery over the CYS domain beginning at 2300UTC.  Overall – a pretty good depiction of the convective evolution in this location – although there appears to be storms too far east over the NE panhandle.  Expect storms to move into that area – but the model was probably a couple hours too quick.

Sim Satellite at 2300 UTC:

Central Colorado developing storms Lightning POS evaluation 23Z 4 June Blog6

Cells have begun to increase in E Central CO. Partner issued warning on strongest cell that showed a rapid increase in Flash Extent. Just after I grabbed image below we saw a lightning jump (Cell just west of the storm with highest flash density.) First good day to evaluate flash extend and light jump. Flash extent seems to be the first indicator of increasing updraft, with the lightning jump coming just later on these cells. My first real experience using LMA data, and it is very handy too have! Display seems quite good as well.

D Satterfield

theta-e ridge

The upper left panel clearly shows a theta-e ridge lifting north from NE CO into SW NE where convection is expected to fire close to 00Z. Stepping through this image clearly show the ridge lifting north indicating a new threat area of possibly severe convection.

jca

EWP Operations Update – Wednesday 6/4 – 6:00 pm

After a few hours of operation in the Louisville, KY (LMK) CWA, it became apparent that severe weather is unlikely there.  Thus, we chose to move that team (Fowle & Anderson) west toward Springfield, MO, where a mesoscale discussion had been issued for hail and wind.

However, not long after that, it became apparent that the capping inversion would hold there.  So, we decided to move again – this time, to the Cheyenne, WY CWA, where convection is ongoing.  Our hope is that we will be utilize the outer extent of the Denver lightning mapping array.

-G. Garfield
Week 4 Coordinator

Flash Density correlating well with prob severe

The progression of images below shows the progression over four volume scans of increasing flash extent density and increasing prob severe percentages over time. While one isn’t necessarily dependent on the other, the strong correlation leads to increasing confidence of severe weather associated with this storm. The lightning jump detection algorithm does not increase here, indicating that a lightning jump doesn’t always precede severe weather. Also, an increase in flash extent density does not equal an increase in lightning strikes,  but an increase in the number of strikes that moved through that specific box.

-KP

my ideal SA display

This 4 panel would be an ideal SA display for forecasters not only as convection is on-going (a non-radar operator), but also as a nowcast tool. We are looking at theta-e difference, CI, sat with overshooting tops and sfc obs, and radar with prob severe.

jca

SA for SGF ops Wed

With a cap still in place, we are seeing where convection should fire based on the above images. The theta-e difference shows a clear instability gradient along a slowly moving cold front. The CI is showing increasing values along that same line as supported by the visible satellite pic.

jca