Read a forecast in 60 seconds
Every forecast answers three separate questions: how catchable crabs may be, whether the trip is safe & workable, and when the water moves best. Here's an example card and the order to read it.
“Confidence” refers to how near-term the forecast day is — nearer days are more dependable. It is not a measure of how likely crabs are to bite.
- Safety color first. Green means generally workable conditions — not "excellent crabbing," and not a guarantee. Red means don't go, even if crab activity looks strong.
- Trip score second. The final "should I go" number, after safety is applied.
- Conditions score third. The estimate of crabbing conditions & expected catchability, before safety.
- Best window last. The current phase & peak-current time tell you when to run a trotline, check traps, or work a shoreline.
It predicts catchability — not guaranteed crabs
The score estimates whether conditions should make blue crabs relatively active & catchable during your morning window. It does not count how many crabs are physically in a river.
The forecast can be right, yet the catch still poor
- Your exact creek may simply hold fewer crabs than the wider river.
- Heavy crabbing pressure may have thinned the local population.
- Bait, gear setup, line depth, or retrieval speed may be off.
- Crabs may be holding a few feet deeper or on another shoreline.
- Jellyfish, algae, turbidity, or runoff may hit your spot harder than regional data shows.
Reading the 0–10 conditions score
| 9 – 10 | Top-tier modeled conditions. |
| 7 – 8.9 | Favorable modeled conditions. |
| 5 – 6.9 | Mixed modeled conditions. |
| Below 5 | Less favorable modeled conditions. |
What goes into the score
The conditions score blends several factors instead of leaning on one piece of folklore like "fish the full moon." These weights reflect the current beta design.
* Salinity & dissolved oxygen are reserved factors, currently omitted when no fresh, representative data are available.
What happens when data are missing?
The model never invents a fake "neutral" value. It removes the missing factor and re-balances the remaining weights — so a broken sensor won't unfairly sink a location, but a high score may rest on fewer inputs than usual.
Why it uses current, not just tide
Tide height is the water rising & falling. Tidal current is the water actually moving sideways — and that's what carries scent and gets crabs feeding. They're related, but high tide and slack current don't happen at the same moment. The model uses NOAA's predicted max flood, max ebb, and slack times.
How the 30% current factor splits
- 20% timing — how much of your 6:00–11:00 AM window overlaps a moving flood or ebb phase.
- 10% strength — whether peak current is strong enough to move scent, without being too ripping for recreational gear.
Local stations vs. timing proxies
Eight waters use a representative local current station. South River & Rhode River borrow Thomas Point-area timing because their in-river stations are flagged weak/variable — so for those two, local tidal range supplies the strength portion instead of trusting offshore speed as if it were inside the river.
Safety is separate from the conditions score
The model keeps the conditions score visible even on unsafe days, so a dangerous day is never disguised as a slow crab day. Your trip score is the conditions score after the safety adjustment is applied:
Safety adjustments are beta model settings — not official NOAA or National Weather Service ratings. A Yellow day is not “85% safe”; it means the model trims the score to reflect added caution.
What the safety gate watches
- Forecast wind during your morning window
- Thunderstorms in the hourly forecast
- Heat (forecast air temp, a temporary stand-in for heat index)
- National Weather Service marine & severe-weather alerts
- Worst condition wins — one danger can't be averaged away by calm elsewhere
The data behind every forecast
What the beta doesn't know yet
- It doesn't directly measure how many crabs are in your creek.
- It doesn't yet include fresh salinity & dissolved-oxygen data across all ten waters.
- Water temperature may be borrowed from the nearest practical station.
- Predicted current is not the same as real-time measured current.
- Wind & alerts can change after the forecast is made.
- The weights & thresholds aren't yet calibrated against a big real catch dataset.
- It doesn't know your bait, gear, technique, depth, local pressure, or boat.
Rules & responsibility
Always check current Maryland rules for season, legal size, sex, gear, license/registration, hours, and possession limits. Regulations can change — review the current Maryland blue crab regulations & recreational licensing information before each trip.
Rivers, creeks & tributaries:
• May–September: one-half hour before sunrise to sunset.
• April and October–December 15: one-half hour after sunrise to sunset.
Chesapeake Bay mainstem:
• May–September: one-half hour before sunrise to 5 p.m.
• April and October–December 15: one-half hour after sunrise to 5 p.m.
Handlines, dip nets, and annually registered crab pots on private property may be used 24 hours a day. Rules may change, so confirm the current regulations before each trip.
In Maryland's Chesapeake Bay and tidal tributaries, no recreational crabbing is allowed on Wednesdays except when using handlines, dip nets, or crab pots from private property, or during a week when a state or federal holiday falls on Wednesday or Thursday.
View current Maryland Chesapeake Bay crabbing rules →