Flagstaff Update

Convection has remained of the pulse-variety. However both Sandwich IR and Day Land Cloud imagery have indicated strengthening cell across the far northern portion of the CWA. Also looked at the derived product-Cloud Top Phase which confirms that the cloud tops are becoming more glaciated. NUCAPS MetOp-A data suggests that steeper mid level lapse rates exist across this portion of the CWA (7-7.5 C/Km), but instability is a little bit lower as well as the PW values. This agrees fairly well with the SPC RAP mesoanalysis.

Forecast Discussion Flagstaff CWA

Main concern will be severity of convection across bulk of cwa through the afternoon. Shear profiles overall weak as large ridge dominates the area with light easterly flow aloft. While SPC and RAP analysis indicate 1500-2500 J/KG CAPE present, GOES 16 Derived CAPE values much lower, generally a third or less what other analysis provide (See below images)

GOES 16 Total precipitable water was useful in identifying plume of moisture advecting into the southern CWA.

A loop of water vapor imagery indicated a short wave trough drifting east into the area, it showed up most apparently in the simple water vapor RGB :

RAP 1.5 PVU pressure fields supported a PV anomaly/trough in this area as well

JRM

Flagstaff Convection: Strong cell

Almost warned on a storm in the western area of the CWA. Cloud tops continued to cool and the PROBSevere for 33% hail highlighted very well over MRMS reflectivity of -64 DBz at the -20C. Based on an environment characterized by weak mid level lapse rates and hardly any shear, figured it just pulsed up for a scan or two then came back down. Could have put out some hail and it collapsed. Overall...IR satellite drew my intial intention to this store, and then I was very pleased how well the PROBSevere highlighted over the strongest are of the storm. GLM Lightning was glanced at, mostly to verify there was decent electrification still occurring/coinciding with the other trends.

Omaha 19Z Satellite analysis

A 4-panel water vapor loop containing upper level (top left), mid level (top right), low level (bottom left) and the simple water vapor RGB (bottom right) depict a remnamt MCV from overnight convection making its way across the lower MO river valley, exiting the Omaha/Topeka CWAs. One interesting thing to note is the upper level anticyclonic rotation in the upper and mid level WV, while a cyclonic low level circulation is evident in low level WV imagery crossing northern MO. This gives a nice 3-dimentional picture of the MCF throughout the depth of the atmosphere.

Red-vis imagery shows a lingering boundary extending from central WI back through northern IA and into far northeast NE around 1930Z.

Comparing this with the day cloud phase RGB (above) shows only isolated cases of glaciation along this boundary across northern IA, and no glaciation noted across northeast NE. Will keep an eye on this product to see if an increase in glaciation can be noted across NE over the next couple of hours.

-64BoggsLite

OAX

Just doing a quick analysis of OAX area. Departing MCV leaving the CWA to the east, so looking at how/when atmosphere will recover. Looking at GOES16 stability indices, seeing that much of the CWA lacks data due to clouds associated with convective debris. Looking at advective area to the south, see a huge difference in CAPE along NE-KS border... with GOES giving us 600-700 j/kg, while GFS model give us 200-3000 j/kg, a huge disparity.

NUCAPS soundings arrived over the CWA at 1848Z. Wanted to sample point nearest Beatrice in the far SE corner of Nebraska, since warm moist parcel was advecting from that area, and NUCAPS point was very near the Beatrice surface ob, which was reporting 89/74. NUCAPS sounding underreported skin conditions as 81/65. Manually edited T and Dp to match Beatrice ob, resulting in SBCAPE of 3883. Experimental NUCAPS came in a few minutes later, reporting SBCAPE as 3883 j/kg, probably closer to reality, although the sounding did not look much like the real world.

Flagstaff Initital Conditions

Some convection has already begun across the Flagstaff WFO. The 4 panel WV loop has proved particularly useful already-namely the simple WV loop in showing a subtle wave moving west from New Mexico. This could help generate convection through the afternoon. Can also see it in the mid and upper level WV loop. Storms across the far western portion of the CWA appear strongest based on MRMS -20C reflectivity, GLM lightning and the sandwich GOES imagery.

Week 4 Day 2 Operations

For day 2 of the GOES-R/JPSS Experiment in the HWT, forecasters will begin working in the Omaha, NE and Flagstaff, AZ CWAs.

-Michael

Day 1 wrap up and feedback

Day one of the experiment wrapped up with forecasters operating in Albany, NY and Grand Forks, ND areas. There were many reports with strong storms that formed in ND and western Minnesota, while storms remained fairly marginal across the Albany CWA. Feedback from yesterday's activities is posted below.

GLM

Thought it was useful, but with the clusters of storms it was a little hard to tell which storms had the big increase

Hard to see the individual cells within a line in the lightning activity

Be nice to have some kind of lightning trend product to be able to follow the trends on certain storms

ProbSevere

First experience using it and thought it did pretty well highlighting the stronger cells

Time series plot would be useful

Like seeing the full readout and everything going into it

Seemed to be a lot less “hot” on going up on marginal looking storms

ProbTor keyed in on the one supercell after it moved out of the CWA, that had a tornado warning on it

Might need a separate training set for the western US for different storms

Did really well in Albany highlighting the threat

Coincided well with the cooling cloud tops

Liked having both options for the long readout and the shorter readout for when its overlaid on other data.

NUCAPS

Experimental soundings did much better highlighting the increased CAPE values

Showed a good warm nose in the mid levels

Probably more useful before convection begins than when you get into warning mode

Latency is a limiting factor for now

Maybe don’t assume a well mixed boundary layer for the experimental sounding, and try to use something a little more meteorologically plausible

ABI

The IR and Visible overlay was really helpful for seeing the overshooting tops/cooling tops and retaining the texture of the clouds

The simple water vapor RGB was useful for pointing out subtle features

The TPW worked really well and seemed to match up well

CAPE was too low and shifted away to the east

The temporal resolution allowed many features to show up really well like boundaries

-Michael

sandwich procedure

I thought the sandwich procedure provided an interesting way to interrogate updraft strength. Overshooting tops stand out well and are easy to assess. It's a nice tool to quickly pick out the strongest updrafts for further interrogation.

64BoggsLites

ProbSevere - Grand Forks CWA

Overall thought the ProbSevere model did well for the event today. Did not see any rapid jumps that really caught me off guard. Thought it did a good job early on the event on keying in on storms that had a more marginal threat. Noticed on a few cells where ProbSevere was around 50% and MESH was over the severe threshold. Seems like past versions of model where quick to max out probabilities once that parameter went over an inch, which may have neglected environments where melting may be taking place.

Definitely allowed me to prioritize which updrafts needed the most attention.

-JRM